Q15) you say there are commonalities between Christianity and Islam but we see major differences.

A) The commonalities are on the name of Jesus and his teachings and differences are also due to his teachings. So in reality there is Biblical Christianity which is not reflective of teachings and sayings of Jesus. Jesus never said I am God. He said he came only for Jews and none else. Paul never met him and whether he did meet or not still he had no right to negate the teachings of Jesus.