New Testament Believers Aren’t Born. They are Born Again.
Within living memory, Jews who believed in Jesus self-identified as Hebrew Christians. Today most former Hebrew Christians now self-identify as Messianic Jews. Their beliefs remain the same--only the label for those beliefs has changed.
According to the (now) Messianic Jewish Theologian Arnold Fruchtenbaum, writing as a Hebrew Christian in 1983, “ A person who at some point in his life personally received Christ as the one who made atonement for his sin experiences what it is to become a Christian. Thus if anyone says that he was born a Christian, this is an obvious sign, according to the New Testament, that he is not a Christian. (Arnold G. Fruchtenbaum, Hebrew Christianity: Its Theology, History, and Philosophy (Tustin, CA: Ariel Ministries, 1983), p. 12.)
How To Be Born Again
Dr. Fruchtenbaum points out that The basic content of faith (that is, what one must believe) is found in 1 Corinthians 15:1–4:
Now I make known unto you, brethren, the gospel which I preached unto you, which also ye received, wherein also ye stand, by which also ye are saved, if ye hold fast the word which I preached unto you, except ye believed in vain. For I delivered unto you first of all that which also I received: that Christ died for our sins according to the scriptures; and that he was buried; and that he hath been raised on the third day according to the scriptures. (Hebrew Christianity, p. 11)
What he must do is described in John 1:12:
“But as many as received him, to them gave he the right to become children of God, even to them that believe on his name.” (Hebrew Christianity, p. 11)
For more on this topic, see Messianic Milestones.