Being born-again makes a Christian a new creation
Born-again is a reference to receiving salvation. In the process of salvation a person experiences a new birth of the spirit of man. This is the born-again experience. The born-again experience is accomplished by accepting Jesus as Savior. This experience opens the door to personal relationship with God. The need for the born-again experience is due to the fact that all human beings are dead in trespasses and sins (Ephesians 2:1).
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 and said to him, “Most assuredly, 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, “Most assuredly, I say to you, unless one is born of water and the Spirit, he cannot enter the kingdom of God. —John 3:1-7
A person who has received this salvation experience is said to be a born-again Christian, or in Christ. Once you are in Christ you become a new creation.
Therefore, if anyone is in Christ, he is a new creation; old things have passed away; behold, all things have become new. —2 Corinthians 5:17