A true Christian is a new creature --- in thought, in word and in deed and exudes the fruits of the spirit in abundance. Indeed scripture says that "Therefore, if anyone is in Christ, he is a new creation. The old has passed away; behold, the new has come. All this is from God, who through Christ reconciled us to himself and gave us the ministry of reconciliation; that is, in Christ God was reconciling the world to himself, not counting their trespasses against them, and entrusting to us the message of reconciliation. Therefore, we are ambassadors for Christ, God making his appeal through us. We implore you on behalf of Christ, be reconciled to God. For our sake he made him to be sin who knew no sin, so that in him we might become the righteousness of God. 2 Corinthians 5:17-21
When we accept Christ into our lives, we become new. A Divine exchange takes place. Christ takes on our sin, and imputes his righteousness upon us so that on the day of judgement when we stand before God, we wear the righteous garments of the one who had no sin --- Christ Jesus himself. We appear to God as having never sinned.
The term Born-Again holds special significance to those of us who were Baptized as Adults, but should also hold significance to those who were Baptized as Children and accepted Christ into our lives as adults. "Now there was a man of the Pharisees named Nicodemus, a ruler of the Jews. This man came to Jesus by night and said to him, “Rabbi, we know that you are a teacher come from God, for no one can do these signs that you do unless God is with him.” Jesus answered him, “Truly, truly, I say to you, unless one is born again he cannot see the kingdom of God.” Nicodemus said to him, “How can a man be born when he is old? Can he enter a second time into his mother's womb and be born?” Jesus answered, “Truly, truly, I say to you, unless one is born of water and the Spirit, he cannot enter the kingdom of God. That which is born of the flesh is flesh, and that which is born of the Spirit is spirit. Do not marvel that I said to you, ‘You must be born again.’ The wind blows where it wishes, and you hear its sound, but you do not know where it comes from or where it goes. So it is with everyone who is born of the Spirit.” John 3:1-8
So how are we who are Born-Again and In Christ supposed to be a new creature? We are supposed to exhibit the fruits of the spirit and grow in the likeness of Christ every day. "But the fruit of the Spirit is love, joy, peace, patience, kindness, goodness, faithfulness, gentleness, self-control; against such things there is no law." Galatians 5:22-23