Coexist?
Impossible. They cannot all be true since they simply contradict each other. If we are to believe the words of Our Lord said in John 14:6: “I am the way and the truth and the life. No one comes to the Father except through me", this simply cannot be. There is only ONE truth. If Our Catholic religion is the True One, then the Moslem cannot be since there is an irreconcilable contradiction, unless of course, one happens to be a Modernist who believes in the plurality of individual "truths" or that words do not mean what they say, in which at the end NOTHING AT ALL is true. Simple Logic.