"...it is an important reminder that for many Christians in the early generations, even for most, the matter of becoming a Christian was not so much the repudiation of an old way of life as, an affirmation that a hoped-for outcome had occurred. Probably, a majority of Christians in the first century were Jews, proselytes or "God-fearers" who came to understand that in Jesus God brought about a new state of affairs in the world. Their experience of 'conversion' was no less dramatic or significant for all of that, but they did not so much renounce an old religion as undertake a radical new understanding of it."

- Jon A. Weatherly, "The Role of Baptism in Conversion", from, "Evangelicalism & The Stone-Campbell Movement".

Surely one can understand that, ‘the matter of becoming a Christian’, according to scripture itself absolutely, inherently of necessity and command, repudiates not only ‘an old way of life’ but in fact ‘one’s old self’.

4 Therefore, we were buried with Him through baptism into death, that just as Christ was raised from the dead by the glory of the Father, even so we also should walk in newness of life.

5 For if we have been united together in the likeness of His death, certainly we also shall be in the likeness of His resurrection, 6 knowing this, that our old man was crucified with Him, that the body of sin might be done away with, that we should no longer be slaves of sin. Romans 6:4-7

Key Points

We also should walk in newness of life:  The Old covenant/Law could not forgive sin: You cannot have newness of life without forgiveness of sin through baptism.

Our old man was crucified with Him: The Old Covenant was our ‘tutor’ to Christ with ‘sin’ only being rolled ahead year-after-year to the cross. In the sacrifice of Christ on the cross, was the forgiveness of sin.

That we should no longer be slaves of sin: The Old Law/Covenant consigned us all to sin. "For the law of the Spirit of life in Christ Jesus has made me free from the law of sin and death". Romans 8:2

But now in Christ Jesus you who formerly were far off have been brought near by the blood of Christ. … by abolishing in His flesh, the enmity, which is the Law of commandments contained in ordinances, Ephesians 2:13, 15

For where there is a testament, there must also of necessity be the death of the testator. 17 For a testament is in force after men are dead, since it has no power at all while the testator lives. Hebrews 9:16-17. This said regarding the New Covenant/Law of Christ. As two wills/covenants cannot be in force at the same time, it’s obvious where the old one (the enmity) stands (Eph 2:15).