In past posts I have attempted to boil being born again down to the moment of water baptism. I think being born again is more complex than just baptism, but as we see in Mark 16:16 it plays a crucial part.
Mark 16:16 tells us, He that believeth and is baptized shall be saved; but he that believeth not shall be damned.
What must we believe?
We must believe Jesus is the Messiah. We must believe he laid down his life for us. We must learn and follow his word.
Why must we be baptized?
See Acts 2:37-39 KJV – . . . Men and brethren, what shall we do? Then Peter said unto them, Repent, and be baptized every one of you in the name of Jesus Christ for the remission of sins, and ye shall receive the gift of the Holy Ghost. For the promise is unto you, and to your children, and to all that are afar off, even as many as the Lord our God shall call
Jesus sets the core of being born again as repentance. In Luke 13:3 KJV he said, I tell you, Nay: but, except ye repent, ye shall all likewise perish.
In Luke 15:7 KJV he added, I say unto you, that likewise joy shall be in heaven over one sinner that repenteth, more than over ninety and nine just persons, which need no repentance.