There's so much wrong with your post one hardly knows where to begin.  If by the 'founder' you mean the Most Noble Messenger Muhammad, he needs no 'excuse' because he never did anything wrong.  And he certainly never invaded Europe, China, Russia or Germany.  He never set foot further from his home in the Arabian peninsula than Palestine.

You forget European Jews fled to Muslim-controlled Quds (Jerusalem) for PROTECTION from the Christian pogroms of Europe.  When Christian Crusaders marched forth to the first Crusade 1032, they slaughtered 12,000 Jews as they passed through the Rhine valley.  They killed at least 6,000 more Jews when they arrived at Jerusalem, as well as 30,000 Muslim men, women and children.  Your Crusaders expressed their "Christain love" by roasting Muslim children alive on spits.

And my God is the God of Abraham.  That's the only One there is.  One of his Holy Names in both the Hebrew OT scriptures and the Arabic Qur'an is 'AL-RAHIIM'; the Infinitely-Merciful.