Quote from article: Before the inception of Islam, most Arabs were polytheistic pagans, believing in an unfeeling, powerful fate that could not be controlled or altered or influenced by human beings. Muslims regard Muhammad as the last and greatest prophet, and they credit him with restoring to the Arabs the monotheistic faith of their ancestors. Islam and Judaism both trace their spiritual lineage to Abraham, but the God-concept of Islam is different from that of Judaism and Christianity in some significant ways. Yahweh and Allah are both seen as omnipotent, omnipresent, omniscient, and merciful. However, in both Judaism and Islam, God’s mercy is dependent, at least partly and many times fully, on man’s actions. The Islamic concept of Allah and the Jewish concept of Yahweh both deny the triune nature of God. They eliminate God’s Son, Jesus, and they also eliminate the Holy Spirit as a distinct Person of the Godhead.
It is true that Arabia at the time of Muhammad (prior to the revelation of the Qur'an) was primarily polytheist but is it also true that its transformation to a monotheist society was very swift and occurred while Muhammad was still alive. The author seems to be getting slick by stating that the concept of God in Islam is not the same as that of Judaism and Christianity. In fact, the concept of God is the same between Islam and Judaism and even what Jesus understood. The concept of God in Christianity is the one that is different from that of Islam and Judaism and it is even different from what Jesus believed in. Secondly, not only does Islam and Judaism deny the triune nature of God but Jesus also denied the triune nature of God. Jesus did not believe that he was a distinct person of the Godhead so he has the same belief as Muslims and Jews. This means that Jesus beliefs are completely different from that of Christians.