Many people assert that Christianity was derived from Judaism, and that Judaism is the older religion of the two. This opinion is universal among secular scholars, and unfortunately many Christians have come to accept this falsehood as well. An accurate understanding of the Bible reveals that Christianity and the religion of the ancient Israelites are one and the same and that it is Judaism that is a more recent schism from the True Faith. Christianity stretches all the way from Abraham up to the modern-day followers of Jesus, whereas the religion known as Judaism was invented the first moment a Hebrew heard the words of Jesus and rejected them.
The Old Testament nation of Israel is the root of faith, of which we become partakers when made members of the Church. Paul uses the imagery of a root and its branches when discussing the apostasy of the Jews and the conversion of the Gentiles, saying,
some of the branches be broken off, and thou, being a wild olive tree, wert graffed in among them, and with them partakest of the root and fatness of the olive tree...because of unbelief they were broken off, and thou standest by faith.
-Romans 11:17, 20
Here we see that the faithless Jews are no longer members of Israel, no longer partakers of the life of the covenant. Paul says that those who lack faith in Jesus Christ—who is the fulfillment of the ancient promise—are not to be considered Israel:
they are not all Israel, which are of Israel: Neither, because they are the seed of Abraham, are they all children....They which are the children of the flesh, these are not the children of God: but the children of the promise are counted for the seed.
Those Jews who are physical descendants of Abraham but who reject Jesus are not true sons of Abraham. The true sons of Abraham are those who imitate Abraham's obedience to God when they accept God's Anointed One who came into the world for our salvation.
The tree to which the ancient Israelites belonged is the same tree onto which Christians are grafted. Through the sacred history we can trace the development of this root of faith: from Abraham, to Moses, to David, to the Prophets, to Christ, to the Apostles, and thence to the Church. This flourishing tree, planted and tended by the Lord, stretches forth from our father Abraham to the congregations of the faithful the world over; but those who reject the Son of God, the light of the world, in no way are nourished by the sap of this tree, and therefore live in darkness.