do religious people really believe?

[Nobody]

I've always suspected that some religious people don't actually believe but just act like they do because that's how they were raised or that's what their friends do. Maybe they are so afraid of death they pretend to believe just in case it is true. I find it hard to believe that the majority of people on this planet in this day of knowledge actually wholeheartedly believe these fairy tales.

It's not so hard to fathom I don't think. People need to feel they are in control and have at least a half way plausible answer to even the most minute questions.
Where did everything that is come from? Is the ultimate question. And in lieu of an absolute answer that goes even beyond the big bang theory, answering in the name of faith with an invisible creator of it all and that bears the characteristics of humanity while being a supernaturally empowered invisible one who serves as parent,dictator, and prosecutor when we're naughty, fills the gap.

Very often people can't bear to imagine they're responsible for their actions and have to answer for them as well. If they paint boogymen as cause for bad behavior, and saviors for the good, they can remove themselves from being the sole cause for everything they experience.
While humans are fallible, fickle, moody, egotistical, it's easier to imagine something invisible but trusted to be there, cares about them when people may not.
While nature, the great and powerful, is wholly indifferent to the human condition.
So basically, an imaginary friend for some seems to be far better than cold indifferent reality, where one has to face themselves as either their worst enemy or best friend. Along with over 7 billion other people doing the same exact thing.

And besides, if for instance bible god carried all the scriptural characteristics as a regular mortal, he'd be either incarcerated, medicated in an insane asylum,or making headlines as a serial killer. However, one thing is certain. He wouldn't be worshiped and adored.
If anything bible god proves the real undercurrent of the mentality that cleaves to man made religion; people see what they need to see, so as to fill the holes they can't face in themselves.