Christianity Is Not Hereditary

Jesus answered, "Very truly, I tell you, no one can enter the kingdom of God without being born of water and Spirit. What is born of the flesh is flesh, and what is born of the Spirit is spirit."
(John 3:5,6 NRSV)

Here [Jesus] tells us that the new birth is first of all "not of [the flesh]." You don't get it through the blood stream, through heredity. Your parents can give you much, but they cannot give you this. Being born in a Christian home does not make you a Christian.

- E. Stanley Jones in "Conversion"