This section has 4 verses.
 
 Titus 2:11-14
 11 For the grace of God that bringeth salvation hath appeared to all men,
 12 Teaching us that, denying ungodliness and worldly lusts, we should live soberly, righteously, and godly, in this present world;
 13 Looking for that blessed hope, and the glorious appearing of the great God and our Saviour Jesus Christ;
 14 Who gave himself for us, that he might redeem us from all iniquity, and purify unto himself a peculiar people, zealous of good works.
 
 We will begin with the Barclay commentary.
 
 THE MORAL POWER OF THE INCARNATION
 
 First the verses paraphrased:
 
 Titus 2:11–14
 For the grace of God, which brings salvation to all men, has appeared, schooling us to renounce godlessness and worldly desires for forbidden things, and to live in this world prudently, justly and reverently, because we expectantly await the realization of our blessed hope – I mean the glorious appearing of our great God and Saviour Jesus Christ, who gave himself for us to redeem us from the power of all lawlessness, and to purify us as a special people for himself, a people eager for all fine works.
 
 THERE are few passages in the New Testament which so vividly set out the moral power of the incarnation as this does. Its whole stress is the miracle of moral change which Jesus Christ can work.
 
 This miracle is repeatedly expressed here in the most interesting and significant way. Isaiah once exhorted his people: ‘Cease to do evil, learn to do good’ (Isaiah 1:16–17). First, there is the negative side of goodness, the giving up of that which is evil and the liberation from that which is low; second, there is its positive side, the acquisition of the shining virtues which mark the Christian life.
 
 First, there is the renunciation of all godlessness and worldly desires. What did Paul mean by worldly desires? The early Church member, John Chrysostom, said that worldly things are things which do not pass over with us into [the Kingdom] but are dissolved together with this present world. People are very short-sighted if they set their hearts and expend all their energies on things which they must leave behind when they quit this world. But an even simpler interpretation of worldly desires is that they are for things we could not show to God. It is only Christ who can make not only our outward life but also our inward heart fit for God to see.
 
 That was the negative side of the moral power of the incarnation; now comes the positive side. Jesus Christ makes us able to live with the prudence which has everything under perfect control, and which allows no passion or desire more than its proper place; with the justice which enables us to give both to God and to our neighbors that which is their due; with the reverence which makes us live in the awareness that this world is nothing other than the temple of God.
 
 The dynamic of this new life is the expectation of the coming of Jesus Christ. When a royal visit is expected, everything is cleaned and decorated and made fit for royal eyes to see. Christians are men and women who are always prepared for the coming of the King of Kings.
 
 Finally, Paul goes on to sum up what Jesus Christ has done, and once again he does it first negatively and then positively.
 
 Jesus has redeemed us from the power of lawlessness, that power which makes us sin.
 
 Jesus can purify us until we are fit to be the special people of God. The word we have translated as special (periousios) is interesting. It means reserved for, and it was used for that part of the spoils of a battle or a campaign which the king who had conquered set apart especially for himself. Through the work of Jesus Christ, Christians become fit to be the special possessions of God.
 
 The moral power of the incarnation is a tremendous thought. Christ not only liberated us from the penalty of past sin; he can enable us to live the perfect life within this world of space and time; and he can so cleanse us that we become fit in the life to come to be the special possession of God. ~Barclay Commentary
 
 Now to the other commentaries. We begin with the general and go to the specific.

This from the Matthew Henry Main. This commentary covers verses 11-14. I will give you the first part of this commentary which discusses the meaning of verse 14.

II. From the end of Christ's death: Who gave himself for us, that he might redeem us from all iniquity, and purify unto himself a peculiar people, zealous of good works, Titus 2:14. To bring us to holiness and happiness was the end of Christ's death, as well as the scope of his doctrine. Here we have,

The ends of his giving himself for us,

(1.) That he might redeem us from all iniquity. This is fitted to the first lesson, denying ungodliness and worldly lusts. Christ gave himself to redeem us from these, therefore put them away. To love and live in sin is to trample under foot redeeming blood, to despise and reject one of the greatest benefits of it, and to act counter to its design. But how could the short sufferings of Christ redeem us from all iniquity? Answer, Through the infinite dignity of his person. He who was God suffered, though not as God. The acts and properties of either nature are attributed to the person. God purchased his church with his own blood, Acts 20:28. Could payment be made at once, no need of suffering for ever. A mere creature could not do this, from the finiteness of his nature; but God - man could. The great God and our Saviour gave himself for us: this accounts for it. By one offering he hath for ever perfected those that are sanctified, Hebrews 9:25-26; Hebrews 10:14. He needed not to offer himself often, nor could he be holden of death, when he had once undergone it. Happy end and fruit of Christ's death, redemption from all iniquity! Christ died for this: and...

Quoted verses:
Hebrews 9:25-26
25 Nor yet that he should offer himself often, as the high priest entereth into the holy place every year with blood of others;
26 For then must he often have suffered since the foundation of the world: but now once in the end of the world hath he appeared to put away sin by the sacrifice of himself.

Hebrews 10:14
For by one offering he hath perfected for ever them that are sanctified.

(2.) To purify to himself a peculiar people. This enforces the second lesson: To live soberly, righteously, and godly, in this present world. Christ died to purify as well as to pardon - to obtain grace, to heal the nature, as well as to free from guilt and condemnation. He gave himself for his church, to cleanse it. Thus does he make to himself a peculiar people, by purifying them. Thus are they distinguished from the world that lies in wickedness; they are born of God, and assimilated to him, bear his image, are holy as their heavenly Father is holy. Observe, Redemption from sin and sanctification of the nature go together, and both make a peculiar people unto God: freedom from guilt and condemnation, freedom from the power of lusts, and purification of soul by the Spirit. These are a chosen generation, a royal priesthood, a holy nation, and so a peculiar people. And,

(3.) Zealous of good works. This peculiar people, as they are made so by grace purifying them, so must they be seen to be so by doing good, and a zeal therein. Observe, The gospel is not a doctrine of licentiousness, but of holiness and good life. We are redeemed from our vain conversation, to serve God in holiness and righteousness all the days of our life. Let us see then that we do good, and have zeal in it; only looking that zeal be guided by knowledge and spirited with love, directed to the glory of God, and always in some good thing. And thus of the motive to the duties directed, from the end of Christ's death. ~Matthew Henry Main with  editing by me

 Now the Matthew Henry Concise. This commentary covers the rest of Chapter 2, verses 11-15.
 
The doctrine of grace and salvation by the gospel, is for all ranks and conditions of men. It teaches to forsake sin; to have no more to do with it. An earthly, sensual conversation suits not a heavenly calling. It teaches to make conscience of that which is good. We must look to God in Christ, as the object of our hope and worship. A gospel conversation must be a godly conversation. See our duty in a very few words; denying ungodliness and worldly lusts, living soberly, righteously, and godly, notwithstanding all snares, temptations, corrupt examples, ill-usage, and what remains of sin in the believer's heart, with all their hindrances. It teaches to look for the glories of another world. At, and in, the glorious appearing of Christ, the blessed hope of Christians will be complete: To bring us to holiness and happiness was the end of Christ's death. Jesus Christ, that great God and our Saviour, who saves not only as God, much less as Man alone; but as God-man, two natures in one person. He loved us, and gave himself for us; and what can we do less than love and give up ourselves to him! Redemption from sin and sanctification of the nature go together, and make a peculiar people unto God, free from guilt and condemnation, and purified by the Holy Spirit. All Scripture is profitable. Here is what will furnish for all parts of duty, and the right discharge of them. Let us inquire whether our whole dependence is placed upon that grace which saves the lost, pardons the guilty, and sanctifies the unclean. And the further we are removed from boasting of fancied good works, or trusting in them, so that we glory in Christ alone, the more zealous shall we be to abound in real good works. ~Matthew Henry Concise

I found some items in the Biblical Illustrator

Christ’s gift of Himself for our redemption
I. The person here spoken of “The great God,” etc.

II. The gift.
1. The dignity of the person bestowing it.
2. The sacrifice at which it is made.
3. Its value.
4. The motive which impelled the donor to bestow it—love.
5. The benefit which accompanies it. ~Biblical Illustrator

Christ’s gift of Himself for us
I. The person referred to. Show
1. His Divinity.
2. His humanity.
3. Union of both.
4. Superiority to angels and all other existences.

II. What this person did. “Gave Himself for us.”
1. Voluntarily.
2. Personally.
3. Sacrificially.

III. The purpose for which he gave himself for us.
1. To “redeem” or deliver us; not from poverty, or affliction, or death, but from “iniquity”—all iniquity—its guilt, condemnation, power, inbeing, consequences.
2. To “purify” us; to separate us unto Himself from the world and sin; “a peculiar people”—in nature, names, possessions.
3. “Zealous of good works”—not passive, but active.

Lessons: Our redemption is
1. Wrought out by love and blood.
2. Entire and perfect.
3. Into blessed experience and useful living. ~Biblical Illustrator

Why believers are called a peculiar people
1. Because they are the most precious of men, even the most noble persons of the earth, descended of the blood of Christ.

2. In regard of God they are a peculiar people, distinct from others by His grace of election by which they are chosen out of the world and set high in His favour above all others. For they lie before Him in the righteousness of Christ in whom the Father is well pleased; they are bought from the earth and stand before Him in the work of His own fingers, namely, their new birth and second creation in which He also delighteth to behold. Hence are they called a holy nation, the spouse of Christ, the daughter of God, the choice of God, and God’s delight.

3. They are a peculiar people in regard of their whole manner and condition of life, which made Balaam say of Israel that it was a people dwelling alone and numbered not himself among other nations, that is, altogether different in laws, customs, manner, and condition of life. But let us see this truth in some instances.

(1) Their original are not some few families coming out of some corner of the earth; but they sprung of Christ, of whom all the families in heaven and earth are called.
(2) Their country is no part of earth, for they are here but strangers and pilgrims, but [The Kingdom], to which they tend and from whence they look for a Saviour.

(3) Their King is neither born nor created, but the everlasting King of glory who ruleth not some one country but from sea to sea, yea, to the world’s end, and not for an age, but as He is a King forever and His kingdom an everlasting kingdom, so He ruleth forever and ever, and of His kingdom there is no end.
(4) Their laws are spiritual, to govern the conscience as well as the outward man, most perfect, never changed, never abrogated as men’s be.

(5) Their war and weapons are not carnal, but spiritual, as their chiefest enemies; their Captain was never foiled nor can be, and therefore before they strike a blow they are sure of victory, and for their external enemies they conquer them, not by smiting (as others), but by suffering.
(6) Their language is the language of Canaan, their speech bewrayeth [to reveal or expose] them to be citizens of [The Kingdom], hence are they called people of a pure language, no filthy, unsavoury, or corrupt communication cometh out of their mouths, but such as is holy, tending to edification, and ministering grace to the hearers.

(7) Their apparel is devised and put on by God Himself, even garments of innocency, long white robes died red in the blood of the Lamb.
(8) Their diet not rising out of the earth, but descending from heaven; Jesus Christ is the Bread of Life, and that manna that came down from heaven, and that water which gusheth out of the rock, of whom whosoever feedeth and drinketh he hath tasted of the tree of life and of the water of life, he cannot but live everlastingly. ~Biblical Illustrator

Now to one of the specific commentaries.  All this from the Barnes Notes

The verse is broken out in five parts:

1] Who gave himself for us.
2] That he might redeem us from all iniquity.
3] And purify unto himself.
4] A peculiar people.
5] Zealous of good works.

1] Who gave himself for us.
Who gave himself for us - See the notes at Ephesians 5:2.

Quoted verse:
Ephesians 5:2
And walk in love, as Christ also hath loved us, and hath given himself for us an offering and a sacrifice to God for a sweetsmelling savour.

2] That he might redeem us from all iniquity.
That he might redeem us from all iniquity - The word here rendered “redeem” - occurs only here and in Luke 24:21; 1 Peter 1:18. The noun, however occurs in Matthew 20:28; and Mark 10:45; where it is rendered “ransom.” It is here said that the object of his giving himself was to save his people from all iniquity; see this explained in the notes at Matthew 1:21.

Quoted verses:
Luke 24:21
But we trusted that it had been he which should have redeemed Israel: and beside all this, to day is the third day since these things were done.

1 Peter 1:18
Forasmuch as ye know that ye were not redeemed with corruptible things, as silver and gold, from your vain conversation received by tradition from your fathers;

Matthew 20:28
Even as the Son of man came not to be ministered unto, but to minister, and to give his life a ransom for many.

Mark 10:45
For even the Son of man came not to be ministered unto, but to minister, and to give his life a ransom for many.

Matthew 1:21
And she shall bring forth a son, and thou shalt call his name JESUS: for he shall save his people from their sins.

3] And purify unto himself.
And purify unto himself -
(1) Purify them, or make them holy. This is the first and leading object; see the notes at Hebrews 9:14
(2) “Unto himself;” that is, they are no longer to be regarded as their own, but as redeemed for his own service, and for the promotion of his glory; - Notes, 1 Corinthians 6:19-20.

Quoted verses:
Hebrews 9:14
How much more shall the blood of Christ, who through the eternal Spirit offered himself without spot to God, purge your conscience from dead works to serve the living God?

1 Corinthians 6:19-20
19 What? know ye not that your body is the temple of the Holy Ghost which is in you, which ye have of God, and ye are not your own?
20 For ye are bought with a price: therefore glorify God in your body, and in your spirit, which are God's.

4] A peculiar people.
A peculiar people - 1 Peter 2:9. The word here used occurs nowhere else in the New Testament. It means, properly, having abundance; and then one’s own, what is special, or peculiar (Robinson, Lexicon), and here means that they were to be regarded as belonging to the Lord Jesus. It does not mean, as the word would seem to imply - and as is undoubtedly true - that they are to be a unique people in the sense that they are to be unlike others, or to have views and principles unique to themselves; but that they belong to the Saviour in contradistinction from belonging to themselves - “peculiar” or his own in the sense that a man’s property is his own, and does not belong to others. This passage, therefore, should not be used to prove that Christians should be unlike others in their manner of living, but that they belong to Christ as his redeemed people. From that it may indeed be inferred that they should be unlike others, but that is not the direct teaching of the passage.

Quoted verses:
1 Peter 2:9
But ye are a chosen generation, a royal priesthood, an holy nation, a peculiar people; that ye should shew forth the praises of him who hath called you out of darkness into his marvellous light:

5] Zealous of good works.
Zealous of good works - As the result of their redemption; that is, this is one object of their having been redeemed; Notes, Ephesians 2:10. ~Barnes Notes

Quoted verses:
Ephesians 2:10
For we are his workmanship, created in Christ Jesus unto good works, which God hath before ordained that we should walk in them.

Christ gave Himself for us.  He is taking us on a journey away from sin and thereby purifying us so that we can invoke the power of the Holy Spirit in the form of good works

This is the lesson of verse 14.