Jhn 3:5 Jesus answered, Verily, verily, I say unto thee, Except a man be born of water and [of] the Spirit, he cannot enter into the kingdom of God.
My preacher says we are born as a baby in water and in the Spirit when we get saved.
The water being that the water must break before the baby comes through the birth canal and the Holy Spirit brings us into a new birth with salvation.
Some people think that it means the gifts of the spirit, but the Bible makes it clear as Christians we all have different gifts. Like Paul says we all can't be an eye or a hand.
Hope this helps.