Practicing religion yields a lot of net-positive effects, particularly mental anguish and internal turmoil. Otherwise, people wouldn't practice them. With moderate practice, you can easily achieve a state of 100% internal peace.
True, being religious would cause me a lot of anguish and turmoil. Just the idea that I'm not in control of my life. I don't consider that a positive of any kind. That scene from the Matrix really speaks to me and always has :)
I think for people that like it it could have positive effects. Just like team sports would have negative effects for me but positive ones for others (I'm totally not a "team player")
I don’t think that follows. Plenty of people practice religion because they’re terrified of the consequences of not doing it, because they’re have been indoctrinated from a young age to believe that to turn away from God is to be tortured in hell for all eternity. (Or in the case of some religions, you can be straight-up executed for leaving.)