God, being God, can bring good out of evil but to what extent does the good he is able to create mitigate the initial evil and would it be better just to do away with that evil? This is the problem we are faced with in Islam in the West. The religion came about as a Christian heresy or, since it did not come from within Christianity itself but from outside, appropriation might be a better word to use. It based itself on a huge simplification of Christian doctrine which is at once its strength and its weakness. Strength because it makes it easier to comprehend for ordinary people and weakness because it sacrifices depth for surface. Its prophet clearly had some kind of supernatural experience but since his level of spiritual understanding was not very high so the level of inspiration he received as well as his ability to interpret it were also not very high. The first contact he had with the spirit he identified as Gabriel when this spirit choked and nearly suffocated him sounds more demonic than angelic.
Well-meaning people want to find common ground between religions. They will say we all worship the same God only in different ways but just because there are similarities between religions, as there inevitably must be, does not mean they all have equal access to truth. You have to examine the ground from which they grew. The ground of Buddhism was the Buddha, a man of great spiritual insight who gave birth to a profound psychological and philosophical system that reflects his own supreme attainment. Christianity has Christ, the Son of God, who has given the highest spiritual revelation so far to mankind and who, it surely cannot be doubted by the unprejudiced mind, summed up divine being in his person as no one else has. That's even without taking the resurrection into account. Islam has Muhammad, a warlord who broke several of the 10 commandments on a regular basis but who nonetheless preached a form of monotheism to pagan polytheists. However, a comparison between Jesus and Muhammad is so spiritually one-sided it's absurd to think that the religions they inspired can be regarded as in any way equal.
Just because Christians, Jews and Muslims claim the same origins does not mean they have the same spiritual authority for their religions. The latter two are formed from human interpretation of archaic revelation that has been superseded. They have failed to take into account the higher revelation of Christ, and not just by neglect but by deliberate rejection in both cases. This marks them out as founded in error, to say the least. Now, God can straighten a crooked branch, to an extent maybe not completely, and there will presumably be as many potentially good people from these religious backgrounds as there are in Christianity and good people can get the best from their religion. But they will still be working with an inferior product and this should be recognised. Just because there are good and bad people in all religions does not mean that all religions are equally good or bad or equally efficacious in the business of religions which is saving souls, guiding them to the true God.
In modern times all religions have lost most of whatever spiritual power they once had. This means that more and more people if they would get to grips with their spiritual destiny need to start to become aware of the inner path. There are doorways to the inner path in all religions but only Christianity has Christ and Christ is the true light that illuminates the path. He makes it easier to tread and it is also him that awaits at the end. Islam by downgrading Christ to a mere human prophet does not know what it should be working towards. It has no light at the end of its path unlike Christianity. It is true that official church religion is moribund but the figure of Christ is always there to act as a personal saviour. Islam has nothing like this which is why it is a spiritual dead end.
I have written this series of posts about Islam because recent protests around the world have reminded us of the idea, long scoffed at by the smart people, that unless the West wakes up it risks being submerged by an alien and backward culture. The European nations, if they would preserve their cultural and spiritual integrity, urgently need to rediscover their Christian soul. The secular leftism they have embraced will not be strong enough to defend itself against the growth of an ideology which can never tolerate anything that is not itself.