What should people do with questions of the relation of the God of the Bible and the God of the Qur’an? Are YHWH and Allah the same God? This is a hard question to answer. If one read the Christian Bible in Arabic, they would find God as Allah. The words are not important. The question is with regard to the concepts. Some uncritically equate them and others label Allah as a demon.
On a practical level, most missionaries and evangelists working with Muslims would talk as if they were the same, giving the Christians and Muslims an important point of contact. Some theologians and apologists, however, strongly disagree. They would suggest that YHWH and Allah, despite both being the God of Abraham, both being the God of Israel, and both being the God of Jesus, have almost nothing in common. It is true that if you compare the biblical and Qur’anic descriptions of God, they are not exactly the same. The God of the Qur’an demonstrates his personality less, the God of the Bible is more loving. However, one could demonstrate differences (not contradictions) between descriptions of God in the Old and New Testaments. One could argue that they are definitely different Gods because the God of the Bible is a Trinity. However, it is difficult to see a Trinity in the Old Testament. Would we say that Christians and Jews worship different Gods? Yes, there are differences between how Christians and Muslims describe God. But there are also some differences between how Roman Catholics, Calvinists, Arminians, Open Theists and Pentecostals describe the attributes of God. Would we say that each of these traditions/movements worship different Gods?
While one should not ignore the differences between the God of the Bible and the God of the Qur’an, it is difficult to deny that there are remarkable similarities between Allah and God, especially as described in the Old Testament. Both Christians and Muslims would agree that God is a personal God, separate from creation, who is omniscient, omnipresent, and omnipotent. Therefore, I believe it is appropriate for missionaries and evangelists to use our common belief in God as a point of contact for conversation.