I don't see what the value in denying free will is. Fascinating sophomore debate? Yes. Gonna help you survive and thrive on this planet? No.
If we find free will exists, well we continue with the way we have been going. If we find that it doesn't, well we don't change anything because we don't have free will. (Honestly I believe there is middle ground to this question. That some people can exert more free will than others but that you can also train this behavior. But that's another discussion. If this is true, I do find this a meaningful answer though)
There's also this Bertrand Russell quote:
"As against solipsism it is to be said, in the first place, that it is psychologically impossible to believe, and is rejected in fact even by those who mean to accept it. I once received a letter from an eminent logician, Mrs. Christine Ladd-Franklin, saying that she was a solipsist, and was surprised that there were no others. Coming from a logician and a solipsist, her surprise surprised me."
The problem with religion comes when it’s used as a justification for horrible acts—just like one might use the lack of free will to justify horrible acts.