The degree of bad depends on the religion and the believer.
Plus one must not forget that, for most believers, religion preceded adulthood, even maturity. Meaning it was never a choice, but imposed through indoctrination and immediate social pressure.
> Never helpful
It clearly is helpful to believers at times. For example, when a loved one dies, it can be extremely comforting to think you'll see them again soon in a paradisical heaven. Comfort when you're hurting is helpful.
Comforting? Sure.
Yet it can be positive if and only if there's no value in grief.
For someone about to die, I think any grief is probably negative. Any personal growth or development won't be utilized. I think of it kind of like morphine, if you're dying it's fine to keep it flowing even if you are getting seriously addicted to it
Religion has saved the lives of many who converted at swordpoint.
Admission to thinking about science as a belief betrays lacks of understanding of the scientific method, which is founded on rigorous doubt and verification.