John 3:5 says that unless a man be born of water and of the spirit he can’t enter the Kingdom of God. What water is he referring to?
The context of the passage surrounding John 3:5 involves being born again, also known as the second birth. Born of water refers to the first birth, since in the womb babies grow in a bag of fluid very similar in composition to sea water. Just prior to birth, the bag breaks, releasing this water and commencing the birth process.
Born of the Spirit is the second birth, what we call being born again. That’s when we become a true child of God and secure our place in His Kingdom. (John 1:12) Some Jews believed that being born Jewish automatically qualified a person for the Kingdom. The Lord was teaching Nicodemus that a person has to experience both births to enter God’s Kingdom.