No, this is not about religion.
This is about systems. One pattern that I've noticed when helping others with their systems is that believing (as in truly without-a-doubt believing) is key to success. When you doubt a system, you end of questioning it's worth, and this makes it so much harder to stick to.
For example, exercise. A common problem for people I exercise with is feature creep. We start off with a simple and effective routine, but then think: "We're missing X, let's do it", "I think I could do Y more", "It doesn't feel like we're doing enough", etc. There's always more to do, though. What started out as a simple effective routine might end up much more complicated, ineffective, and time consuming than intended. The solution is belief in the system.
A more recent example is that I've been trying the Pomodoro Technique. I've tried it before, and I was underwhelmed1. Recently though, I've been convinced that it made a lot of sense, and sure enough, have been extremely successful with it (so far).
I'm probably the most skeptical person I know, but it would be foolish not to acknowledge the power of blind faith.