Bemused, my point is not whether or not there are gezeiros we don’t understand. My point is that if one decides it is morally OK for one to kill based on the teachings of a holy book, that must carry across the board to the holy books of all religions and give them license to kill, as well. The Crusaders were hence justified in killing Jews, if their holy books say one must die for rejecting Jesus.
One can say I will keep kashrus although I don’t understand, because it is a gezeira. But when one is dealing with killing other humans, one better make sure 100% that he does understand what he is doing and the justification for doing so.
When you hear of a suicide bombing, do you instinctively say these were righteous, religious people who meant well and were dedicated to serving G-d even to the point of giving up their lives for Him, or do you say these were reshaim, scum of the earth who would even kill women and children with no human feelings of mercy? I personally do the latter.