The old man nature must go into oblivion. That which is flesh, is flesh, and cannot enter into the Father's World.
Being born anew is an active verb of becoming out of ourselves into Him.
Marvel not, you must be born anew.
"Your new life is not like your old life. Your old birth came from mortal sperm; your new birth comes from God's living Word. Just think: a life conceived by God Himself!" ~MSG