Born Again Christians are Christians who believe you must be Born-Again in order to go to heaven. The belief is based on the bible verse found in the book of John chapter 3 verse 3 "Jesus answered and said unto him, Verily, verily, I say unto thee, Except a man be born again, he cannot see the kingdom of God".
Born Again Christians believe once you verbally confess to God that Jesus is Lord and you believe Jesus was raised from the dead, you are born again and can now enter heaven. This belief is based upon a bible verse in the book of Romans, Chapter 10 verse 9.
Born Again Christians believe in the bible very literally.
Because Born-Again Christians believe in the bible very literally, you will usually find them on the opposing side of the fight for gay marriage and gay rights. Their beliefs are based on a bible verse found in the bible book of Leviticus charpter 18 verse 22 "Thou shalt not lie with mankind, as with womankind: it is abomination".