Our spirits God has redeemed, but the redemption of the body not yet. Not until the resurrection
The body of death is due to sin and is why it perishes, this goes all the way back to Genesis and the fall.
The sins we do in the body of flesh, but we do not sin in the spirit if we have become new creations in Christ.
That new spirit God created is the new man created in righteousness and holiness and cannot sin.
Romans 8 we are spiritually alive and His when we are born again and believe.
9 But you are not in the flesh but in the Spirit, if indeed the Spirit of God dwells in you. Now if anyone does not have the Spirit of Christ, he is not His.
10 And if Christ
is in you, the body
is dead because of sin, but the Spirit
is life because of righteousness.
1 John 3:9
Whoever has been born of God does not
sin, for His seed remains in him; and he
cannot sin, because he has been born of God.
The spirit is born of God and cannot sin. This is very clear.