Some time ago, I had written a post regarding the Roman Catholic Catechism and Islam, dealing with the Catechism's statements on whether or not Muslims are fellow worshipers of the true God of Abraham. Since then, I've come across many people (mostly Roman Catholics) who continue to say that they, and Jews, do worship the same God as Christians. Mostly they will try to rationalize an argument in order to say this (and we will get to some momentarily) - however, the question ultimately boils down to this question: how do all three religions treat God the Son, aka Jesus Christ?
We must remember that Christians uphold God as a Trinitarian God. That is, God is one Being, made up of three co-equal, co-existent and co-eternal but distinct Persons in the Father, Son, and Holy Spirit. The Trinity, it must be noted, is not Tritheistic with three separate gods, but rather each Person, while being distinct, represents the fullness of God. This is seen in scripture, where in Christ it is said "the whole fullness of deity dwells bodily" (Col 2:9). God the Son, while being distinct from God the Father and God the Holy Spirit, still represents the fullness of God. Christ was not one third of God (which is tritheism), but he was God the Son made flesh.
Jews and Muslims, on the other hand, believe in a Unitarian God. That is, God is not one Being found in three distinct but equal Persons, but rather one Being and one Person. On this basis alone, we can see that the Christians worship a God that is already very different than the Jewish and Islamic gods. To Jews and Muslim, God is not a Trinity, and therefore they would deny not only the Messianic status of Christ (for the Jews) and the deity of Christ (for the Jews and Muslims), but they would deny, and reject worship of, God the Son.
What does scripture say about those who deny God the Son? The overall teaching of scripture is that those who deny the Son are denied by the Father as well. Christ stated that those who denied him before men, he would deny them before his Father (Mt 10:33). He told the unbelieving Jews: "You know neither me nor my Father. If you knew me, you would know my Father also" (Jn 8:19); and likewise, "If God were your Father, you would love me" (Jn 8:42). He told the disciples: "No one comes to the Father except through me" (Jn 14:6); and likewise, "Whoever hates me hates my Father also" (Jn 15:23). The apostle John put it in the most blunt manner when he wrote "no one who denies the Son has the Father. Whoever confesses the Son has the Father also" (1 Jn 2:23). According to the resounding testimony of scripture, those who deny God the Son and reject worship of him reject worship of the true God. Why is this? It is because, as God the Son represents the fullness of God, denial of one Person of the Trinity is denial of God in toto. Those who choose not to worship one Person of the Trinity refuse to worship God in toto.
Many will of course try to rationalize out of this. Some responses to such arguments:
Did the people in the Old Testament worship a Trinitarian God? The fullness of the Trinitarian revelation was not yet given to those under the old covenant, however God still existed as a Trinity, and the people under the old covenant therefore worshiped a Trinitarian God. There are moments in the Old Testament where a pre-incarnate God the Son was even encountered by believers.
Wasn't Jesus a Jew, and didn't he worship as a Jew? Didn't he pray to YHWH, just as the Jews today do? Such questioning, in fact, is ironically similar to arguments made by Muslims against the Trinity (ie., "If Jesus was God, who was he praying to?", etc.). That Jesus lived under the Mosaic Laws is, of course, clear to be seen in scripture, but this was out of the necessity that, as the perfect sacrifice before God, he live post-incarnation as the perfect man, and therefore had to fulfill the Mosaic Law and all it required. Yet if we ask then, whether or not he prayed to YHWH, we have to first realize we are heading down a dangerous road, theologically speaking. That is, we have to ask if we are suggesting that Jesus prayed outside his role in the Trinity? When Jesus prayed, it was the Son praying to the Father - Jews of today do not have this ability. We have to also remember that Jesus, as God the Son, was himself YHWH - those who have evangelized to Jehovah's Witnesses realize how important it is to prove that the holy name of God was attributed to Jesus Christ. To be certain, those who argue "Jesus was Jewish" are simply giving a non sequitor.
Don't Muslims claim to worship the God of Abraham? Let's first ask ourselves from where Islam came - to put it bluntly, it was from a false prophet in ancient Arabia who heard demonic lies in the desert. The god of Islam taught his people teachings so woefully different than the God of Christianity that, on this basis alone, one has to wonder how one can logically conclude the god of Islam and the God of Christianity are the same God, as God would not contradict himself in such a blatant manner. Simply claiming that you'd like to worship the God of Abraham does not automatically mean you are - I could claim my car was the God of Abraham and worship it, that wouldn't mean I was worshiping the same god as that of Christians.
Scripture says rejection of the Son will lead to rejection by the Father, but it says nothing for those who simply don't know any better. Where, however, in all of scripture is this such a distinction made? Such a question demands we find a gray area where the word of God sees only black and white. I am aware there are many pet verses taken by people out of context to prove inclusivist beliefs, therefore I might direct the rest of this conversation to this post.
More importantly, all of these arguments ignore the clear teaching of scripture on this matter. Those who forsake the teaching of scripture for human reasoning in essence forsake God's authority for the authority of man. Especially with Roman Catholics, who are fond of opening up arguments on this subject with "The pope said..." or "My church says...", they seem to unwittingly desire to quote a pope or church over and against the words of scripture. I'm sorry, but scripture trumps any words of man.
It must be noted here, as we conclude this post, that we should still witness to and pray for our Jewish and Muslim friends. They must hear who the true God is, and be invited to worship Him, for only God the Son can purify them of their sins and be made righteous before God the Father, sanctified and sealed by God the Holy Spirit. God bless.