I think I understand what you are trying to say.
Look, we are imperfect beings with limited understanding and sometimes we have to rise above our experiences to understand the truth.
When I was a kid I stuck a nail in a 220VAC outlet and woke up across the room. Is electricity bad? Nope, but that incident did make me wary of how electricity can hurt and kill.
Christianity has been abused and distorted by many throught time for their own ends, e.g. Divine Right, Forced Conversion, Jim Baker, Branch Davidians, and more recently TBN.
Are those examples Christianity? No, they are distortions. Are some of those people considered "fundamentalists?" Yes.
Islam is not being distorted or being practiced in an extreme way. Islam is inherently violent and cruel, with no system of atonement other than the whim of their god.
Christianity is the foundation for western civilization and much of the scientific and social advancements that we enjoy today.