Here is a definition of redemption from HELPS Word-studies:
629 apolýtrōsis(from 575 /apó, "from" and 3084 /lytróō, "redeem") – properly, redemption – literally, "buying back from, re-purchasing (winning back) what was previously forfeited (lost)."
629 /apolýtrōsis ("redemption, re-purchase") emphasizes the distance ("safety-margin") that results between the rescued person, and what previously enslaved them. For the believer, the prefix (575 /apó) looks back to God's effective work of grace, purchasing them from the debt of sin and bringing them to their new status (being in Christ).
2 Cor 3:17 has no mention of "the Spirit of Liberty" (nor will you find that term in all of Scripture).
2 Corinthians 3:
7 But if the ministration of death, written and engraven in stones, was glorious, so that the children of Israel could not stedfastly behold the face of Moses for the glory of his countenance; which glory was to be done away:
8 How shall not the ministration of the spirit be rather glorious?
9 For if the ministration of condemnation be glory, much more doth the ministration of righteousness exceed in glory.
10 For even that which was made glorious had no glory in this respect, by reason of the glory that excelleth.
11 For if that which is done away was glorious, much more that which remaineth is glorious.
12 Seeing then that we have such hope, we use great plainness of speech:
13 And not as Moses, which put a vail over his face, that the children of Israel could not stedfastly look to the end of that which is abolished:
14 But their minds were blinded: for until this day remaineth the same vail untaken away in the reading of the old testament; which vail is done away in Christ.
15 But even unto this day, when Moses is read, the vail is upon their heart.
16 Nevertheless when it shall turn to the Lord, the vail shall be taken away.
17 Now the Lord is that Spirit: and where the Spirit of the Lord is, there is liberty.
18 But we all, with open face beholding as in a glass the glory of the Lord, are changed into the same image from glory to glory, even as by the Spirit of the Lord.
2 Cor 3 tells us that until we turn our hearts to the Lord Jesus Christ, our minds are blinded (2 Cor 3:14) and we read Scripture with a vail on our heart (2 Cor 3:15), and when we turn our hearts to the Lord Jesus Christ, the vail is lifted (2 Cor 3:16) and as we read Scripture with open face, we behold as in a glass the glory of the Lord, are changed into the same image from glory to glory, even as by the Spirit of the Lord (2 Cor 3:17).
Then as we continue to read:
4:1 Therefore seeing we have this ministry, as we have received mercy, we faint not;
2 But have renounced the hidden things of dishonesty, not walking in craftiness, nor handling the word of God deceitfully; but by manifestation of the truth commending ourselves to every man's conscience in the sight of God.
3 But if our gospel be hid, it is hid to them that are lost:
4 In whom the god of this world hath blinded the minds of them which believe not, lest the light of the glorious gospel of Christ, who is the image of God, should shine unto them.
5 For we preach not ourselves, but Christ Jesus the Lord; and ourselves your servants for Jesus' sake.
6 For God, who commanded the light to shine out of darkness, hath shined in our hearts, to give the light of the knowledge of the glory of God in the face of Jesus Christ.
7 But we have this treasure in earthen vessels, that the excellency of the power may be of God, and not of us.
Such a great section of Scripture. Much, much better to read this section in its entirety and not rip verses out of context and then misquote them to prop up a dogma not contained in Scripture.
