The Lord Jesus Christ explained it to saint Nicodemus while he was still the teacher of Israel. The Lord said, "Most truly I say to you, unless one is born from water and Spirit, he cannot enter into the Kingdom of God" so it appears that God is the one who gives both the water and the Spirit by means of which one is born from above. One cannot enter the kingdom of God without being born from above. Saint Paul explains the nature of the birth in these words:
(Romans 6:3-11) . . .do you not know that all of us who were baptised into Christ Jesus were baptised into his death? 4 So we were buried with him through our baptism into his death, in order that just as Christ was raised up from the dead through the glory of the Father, so we also should walk in newness of life. 5 If we have become united with him in the likeness of his death, we will certainly also be united with him in the likeness of his resurrection. 6 For we know that our old personality was nailed to the cross along with him in order for our sinful body to be made powerless, so that we should no longer go on being slaves to sin. 7 For the one who has died is freed from his sin. 8 Moreover, if we have died with Christ, we believe that we will also live with him. 9 For we know that Christ, now that he has been raised up from the dead, dies no more; death is no longer master over him. 10 For the death that he died, he died to sin once for all time, but the life that he lives, he lives to God. 11 Likewise you, consider yourselves to be dead to sin but living to God by Christ Jesus.
So one must be born from above by water and Spirit to see the kingdom of God and the birth is by baptism and it leads to resurrection life after death to sin.