Communism like Christian fundamentalism (in politics) promises a solution to all of life's problems, a quick fix, an end to all suffering, in an ideal future. And you can never question what they say. And, communism, despite what people say, is just another form of political and moral conservativism. They are very intolerant. In fact, in most communist countries (except China) even gay sex is illegal.
The actions of much / most of humanity present many conundrums , however there are those that seek power politically( some by any means necessary ) and those that are susceptible to succumbing to the powerful orations of the religious ----often to deleterious or disastrous results to their well being. At least to those of us that are not easily persuaded, IMO.
