-Jesus, the Son of God, fulfilled the Old Testament prophecies regarding the Messiah.In fact, the Apostle Paul uses an olive tree as an analogy, saying that Gentile believers are "wild branches" grafted into an olive tree (God's people) where some of the "natural branches" (Jews) have been broken off (for rejecting the promised Messiah):
-He was a Jew descended from King David.
-He declared Himself to be YHWH (the name by which the God of Israel revealed Himself to Moses).
-The Apostles were all Jews.
-The entire Christian Bible -- both Old and New Testaments -- is Hebrew/Jewish.
-The first Christians were Jews.
if the root is holy, so are the branches. But if some of the branches were broken off, and you, although a wild olive shoot, were grafted in among the others and now share in the nourishing root of the olive tree, do not be arrogant toward the branches. If you are, remember it is not you who support the root, but the root that supports you. Then you will say, "Branches were broken off so that I might be grafted in." That is true. They were broken off because of their unbelief, but you stand fast through faith. So do not become proud, but fear. For if God did not spare the natural branches, neither will he spare you. Note then the kindness and the severity of God: severity toward those who have fallen, but God's kindness to you, provided you continue in his kindness. Otherwise you too will be cut off. And even they, if they do not continue in their unbelief, will be grafted in, for God has the power to graft them in again (Romans 11:16-23).In contrast, the illiterate pagan Muhammad had some contact with Jews and Christians, so he had only an incomplete knowledge of some of their traditions (which explains partly the obvious corruptions of Biblical stories in Qur'an). Add to that the fact that in the beginning of Muhammad's prophetic career -- when he was politically and militarily weak and his "revelations" were still nonviolent -- he tried to persuade Jews and Christians that he was a genuine prophet from their God by co-opting Abraham. In the same way, today's Islamic propagandists want to lower the affective filters of Jews and Christians (and those familiar with Judaism and Christianity, for if Islam is basically the same as those religions, it can't be bad). That's why Muslims claim Islam as an "Abrahamic faith."
But any comparison of Christianity and Islam's sacred texts shows that the religions' two gods could not be more diametric: Jesus committed no sin, spoke only the truth, healed the sick, raised the dead, died for the sins of the whole world, and resurrected, teaching His people to love even their enemies. On the other hand, Muhammad sacralized the violation of all Ten Commandments and the Golden Rule.
If Muhammad had worshiped Abraham's God, he would have said and done what Abraham said and did. He would have worshiped the Messiah. Islam shares "common roots" with Judaism and Christianity like a car thief "shares" other people's cars