Romans 8 states:
" But ye are not in the flesh, but in the Spirit, if so be that the Spirit of God dwell in you. Now if any man have not the Spirit of Christ, he is none of his.
10 And if Christ be in you, the body is dead because of sin; but the Spirit is life because of righteousness.
11 But if the Spirit of him that raised up Jesus from the dead dwell in you, he that raised up Christ from the dead shall also quicken your mortal bodies by his Spirit that dwelleth in you.
12 Therefore, brethren, we are debtors, not to the flesh, to live after the flesh.
13 For if ye live after the flesh, ye shall die: but if ye through the Spirit do mortify the deeds of the body, ye shall live. " ( Romans 8:9-13 ).
Notwithstanding the Late Middle English of the AV, this tells me that as a believer, not only has God made me alive in my spirit ( Psalm 80:18, John 5:21, Romans 4:17, Ephesians 2:1-5, 1 Timothy 6:13 ), but is making me alive in my body as well;
To the point that if I walk in the Spirit, I will not fulfill the lusts of the flesh ( Galatians 5:16 ).
To answer your thread, I see the Scriptures teaching that a believer grows in both knowledge and grace from a carnal "man" ( 1 Corinthians 3:1-3 ) that walks as natural men do, to a "spiritual" man that does not ( 1 Peter 2:2, 2 Peter 3:18 ), going from children, to young men, to "fathers" ( 1 John 2:1-14 ).
In other words,
We as God's children grow in our knowledge and understanding of the Scriptures, and we also grow in our stature or "person" from being less like Christ to more like Christ.
Our sin becomes less and less, and we put off the things of the flesh that surround the spirit that God has made alive through the new birth, or our being "born again" through the Spirit.
While we may never be completely free of sin until after this life, our sin is lessened over time by the power of the Holy Spirit that lives within each and every one of us.