To redeem them - Εξαγορασῃ· To pay down a price for them, and thus buy them off from the necessity of observing circumcision, offering brute sacrifices, performing different ablutions, etc., etc.

That we might receive the adoption of sons - Which adoption we could not obtain by the law; for it is the Gospel only that puts us among the children, and gives us a place in the heavenly family. On the nature of adoption see the notes on Romans 8:15.

redeem.

Galatians 4:21 Tell me, you that desire to be under the law, do you not hear the law?

Galatians 3:13 Christ has redeemed us from the curse of the law, being made a curse for us: for it is written...

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

Luke 1:68 Blessed be the Lord God of Israel; for he has visited and redeemed his people,

Acts 20:28 Take heed therefore to yourselves, and to all the flock, over the which the Holy Ghost has made you overseers...

Ephesians 1:7 In whom we have redemption through his blood, the forgiveness of sins, according to the riches of his grace;

Ephesians 5:2 And walk in love, as Christ also has loved us...

Colossians 1:13-20 Who has delivered us from the power of darkness, and has translated us into the kingdom of his dear Son...

Titus 2:14 Who gave himself for us, that he might redeem us from all iniquity, and purify to himself a peculiar people, zealous of good works.

Hebrews 1:3 Who being the brightness of his glory, and the express image of his person, and upholding all things by the word of his power...

Hebrews 9:12,15 Neither by the blood of goats and calves, but by his own blood he entered in once into the holy place...

1 Peter 1:18-20 For as much as you know that you were not redeemed with corruptible things, as silver and gold...

1 Peter 3:18 For Christ also has once suffered for sins, the just for the unjust, that he might bring us to God, being put to death in the flesh...

Revelation 5:9 And they sung a new song, saying, You are worthy to take the book, and to open the seals thereof: for you were slain...

Revelation 14:3 And they sung as it were a new song before the throne, and before the four beasts, and the elders...

that we.

Galatians 4:7 Why you are no more a servant, but a son; and if a son, then an heir of God through Christ.

Galatians 3:26 For you are all the children of God by faith in Christ Jesus.

John 1:12 But as many as received him, to them gave he power to become the sons of God, even to them that believe on his name:

Romans 8:19,23 For the earnest expectation of the creature waits for the manifestation of the sons of God...

Romans 9:4 Who are Israelites; to whom pertains the adoption, and the glory, and the covenants, and the giving of the law, and the service of God...

Ephesians 1:5 Having predestinated us to the adoption of children by Jesus Christ to himself, according to the good pleasure of his will,

Adoption --The Spirit and the Cry
The divinity of each of these sacred persons is also to be gathered from the text and its connection. We do not doubt tee the loving union of all in the work of deliverance. We reverence the Father, without whom we had not been chosen or adopted: the Father who hath begotten us again unto a lively hope by the resurrection of Jesus Christ from the dead. We love and reverence the Son by whose most precious blood we have been redeemed, and with whom we are one in a mystic and everlasting union: and …
Charles Haddon Spurgeon—Spurgeon's Sermons Volume 24: 1878

The Gospel Message, Good Tidings
[As it is written] How beautiful are the feet of them that preach the Gospel of peace, and bring glad tidings of good things! T he account which the Apostle Paul gives of his first reception among the Galatians (Galatians 4:15) , exemplifies the truth of this passage. He found them in a state of ignorance and misery; alienated from God, and enslaved to the blind and comfortless superstitions of idolatry. His preaching, accompanied with the power of the Holy Spirit, had a great and marvellous effect. …
John Newton—Messiah Vol. 2

How Can I Obtain Faith?
May the Spirit of God assist us while we meditate upon the way by which faith cometh. This shall be followed by a brief indication of certain obstructions which often lie in that way; and then we will conclude by dwelling upon the importance that faith should come to us by that appointed road. I. First, then, THE WAY BY WHICH FAITH COMES TO MEN. "Faith cometh by hearing." It may help to set the truth out more clearly, if we say, negatively, that it does not come by any other process than by hearing;--not …
Charles Haddon Spurgeon—Spurgeon's Sermons Volume 18: 1872