Do religions alter or destroy the human spirit? If people were free of religion would they excel more, accomplish more, achieve more, and be happier? Why or why not?
Of course it doesn't "destroy" the "human spirit". Humans have been practicing religions for thousands of years. I would argue that the simple fact that disparate groups of humanity, entirely separated from one another all developed belief systems of their own independently of one another points to "religion" very much being a part of being human.
Would
we accomplish more? The "we" pointing, in my interpretation, to society/humanity as a greater whole. The answer there is no also. Many people find enormous amounts of motivation in adhering to and believing in their chosen faith. In fact, there are probably people who feel as though they couldn't function as well without it. It also brings happiness to many people that I know.
In the end, as most others have stated, it depends upon the person. I myself find no value in religion for me outside of finding it interesting to read/hear the wisdom passed down from ages ago. I have certainty about very little as pertains to "why" we are here, or what lies ahead... but neither does that bother me or make me any less happy. I have a strong sense of morality, without rules imposed by an outside force. But to someone else, it probably looks as if I am on a precarious perch. But it is not my place to say that others should live or believe as I do. Not my place at all.