There is this movement within the church now about witnessing to Muslims and with this idea that we worship the same God. The thought is based on the fact that the Qur'an has a link to the God of Abraham, Moses, Joseph and also talked about Jesus even though it deny the sonship.
The Bible says in 1John 22, 23 "Who is a liar but he who denies that Jesus is the Christ? He is antichrist who denies the Father and the Son. Whoever denies the Son does not have the Father either; he who acknowledges the Son has the Father also. How then can we reconcile this fact with the idea that we worship the same God with the Muslims?