God is “the eternal Father of our Lord Jesus Christ” is the confession made by Reformed Christians in Q/A 26 of the Heidelberg Catechism. This is an essential part of our answer to the question, who is God? This also helps answer the question, is the God of Christianity the same as the God of Islam? This question has come to the foreground of public consciousness because of Wheaton College’s decision to suspend a professor for asserting that Christians and Muslims worship the same God. Many commentators treat this as a difficult question. But it is not. The true God is the Father of Jesus Christ. Any god that is not the eternal Father of Jesus Christ is a different god, therefore not God at all.
With Christmas approaching it is worth remembering that Christmas is a uniquely Christian holiday. We celebrate the wonder of the eternal Son of God taking “upon Him the very nature of man” (Heidelberg Catechism, Lord’s Day 14). Muslims do not celebrate Christmas because they do not embrace God’s Son. If we say that Muslims and Christians worship the same God because both religions are monotheistic, then we lose Jesus Christ and have no reason to celebrate his birth.
For more on this I point you to Albert Mohler’s explanation that Christians and Muslims do not worship the same God. Here is an excerpt:
A statement made by a professor at a leading evangelical college has become a flashpoint in a controversy that really matters. In explaining why she intended to wear a traditional Muslim hijab over the holiday season in order to symbolize solidarity with her Muslim neighbors, the professor asserted that Christians and Muslims worship the same God.
Is this true?
The answer to that question depends upon a distinctly Christian and clearly biblical answer to yet another question: Can anyone truly worship the Father while rejecting the Son?
The Christian’s answer to that question must follow the example of Christ. Jesus himself settled the question when he responded to Jewish leaders who confronted him after he had said “I am the light of the world.” When they denied him, Jesus said, “If you knew me, you would know my Father also” (John 8:19). Later in that same chapter, Jesus used some of the strongest language of his earthly ministry in stating clearly that to deny him is to deny the Father.
Christians and Muslims do not worship the same God. Christians worship the triune God, Father, Son, and Holy Spirit, and no other god. We know the Father through the Son, and it is solely through Christ’s atonement for sin that salvation has come. Salvation comes to those who confess with their lips that Jesus Christ is Lord and believe in their hearts that God has raised him from the dead (Romans 10:9). The New Testament leaves no margin for misunderstanding. To deny the Son is to deny the Father.