Humans were made in the image of God (Genesis 1:26, Genesis 2:7) and God is spirit (John 4:24). Who we are is who we are internally, which is spirit and will exist forever. Because of the fall, all humans have been born with a propensity to sin. But because of Jesus’ sacrifice through the Cross and Resurrection, we can have eternal life. Our previously dead spirit will then have eternal life, the very life of God (Romans 8:9, 1 John.4:4, Colossians 1:13). To those who are born again, there is now no condemnation awaiting them (Romans 8:1, Romans 5:9, John 3:17-18, 1Thessalonians 5:9). In this life, we are supposed to live by the guidance of the Holy Spirit (who always leads us in line with the Word of God) from within the regenerated spirit (Romans 6:6-14, Romans 8:8-11,26).
The house we live in, this mortal body, will at the resurrection become immortal (1 Corinthians 15:35-57, 2 Corinthians 5:1-5). But for the time being, this mortal body causes us many challenges. It is subject to death, sickness, embarrassment, temptations, etc. But it can be made to obey the spirit from within. How? By bringing the mind, will, and emotions in line with the regenerated spirit. The re-born spirit already wants to obey God and His Word, but the soul (mind, will, emotions) has to be subjected to the spirit to accomplish that (1 Thessalonians 5:23-24). As we progressively bring the soul in subjection to the spirit, we discover more and more what is available to us today in the Spirit of God. We are told to walk (live) in the Spirit (Galatians 5:16-26). To the degree that we do that, the fruit of the Spirit will be evident in our life, as will the gifts and power of the Spirit!