Our life in Christ (the exchanged life)

Galatians 2:20, "I am crucified with Christ: nevertheless I live; yet not I, but Christ liveth in me: and the life which I now live in the flesh I live by the faith of the Son of God, who loved me, and gave himself for me."

After we repent (confess and turn from) our sins, and believe upon Jesus Christ and the work that He has done for us on the cross, our life is in Christ and we are identified with Him and His righteousness, thereby setting us free from guilt and condemnation. For the scriptures say that those who are in Christ Jesus, are dead to sin and there is no condemnation awaiting them:

Romans 8:1, "There is therefore now no condemnation to them which are in Christ Jesus, who walk not after the flesh, but after the Spirit."

In Roman's chapter 6, we learn that our old self was crucified with Christ and buried with Him, and we are raised to new life in Christ Jesus: Romans 6:3-6, "Know ye not, that so many of us as were baptized into Jesus Christ were baptized into his death? Therefore we are buried with him by baptism into death: that like as Christ was raised up from the dead by the glory of the Father, even so we also should walk in newness of life. For if we have been planted together in the likeness of his death, we shall be also in the likeness of his resurrection: Knowing this, that our old man is crucified with him, that the body of sin might be destroyed, that henceforth we should not serve sin."

When we are raised to new life, also known as the born again experience (see John 3), we are also considered a new person; old things having passed away and all things became new:

2 Corinthians 5:17, "Therefore if any man be in Christ, he is a new creature: old things are passed away; behold, all things are become new."

1 Peter 1:23, "Being born again, not of corruptible seed, but of incorruptible, by the word of God, which liveth and abideth forever."