When various Christians try to engage Islam, pointing out that despite the various (and significant) differences which exists between the two faiths, they still worship the same God, other Christians quickly speak up and say it is impossible because of those very differences. It is as if they believe God is created by one’s own thoughts about God, justifying Feuerbach and others like him in saying God is created in the image of humanity instead of humanity in the image of God. If mere opinion about the various characteristics of God establish belief in a different God, no two people will worship the same God, as no two people have identical notions about God. However, God is beyond us, and our opinions about God do not form or shape who God is but only reveal what we think about God. Those differences can be important as bad ideas about God can lead to all kinds of terrible actions by those who believe them, and for this reason arguments concerning which representation of God best exemplifies the divine nature can matter, but they do not matter in relation to the question of whether or not people are seeking after and believing in the same God. Christians and Muslims share God in common, and indeed, believe many of the same things about the divine nature, including elements which come from revelation (and so not reason alone):
The Church regards with esteem also the Moslems. They adore the one God, living and subsisting in Himself; merciful and all- powerful, the Creator of heaven and earth, who has spoken to men; they take pains to submit wholeheartedly to even His inscrutable decrees, just as Abraham, with whom the faith of Islam takes pleasure in linking itself, submitted to God.[1]
A Center of Christian-Muslim Engagement for Peace and Justice: 