Before I read this topic at TUS I just looked in the internet to investigate about Stephen Hawking and landed on a long Video with him. I watched the whole Video. After that I openened TUS and stumbled upon this topic by accident

There are many reasons why people believe in something.
Some examples:
1) I think people invented gods to explain things which they couldn't understand and explain.
2) There are always clever guys who invent things and theories (which are mainly not true) to get their own advantages out of that because of naiv people who believe them and
pay for useless things (today mainly with money). Not many people are good in logical thought and it is not difficult to manipulate.
If there wouldn't be lying parents, kids wouldn't know about Santa Claus. They just believe in it because when they are too young, they believe what their parents say. The parents tell a whole story about it. The kids just can't know how it really works but they see there are gifts and that the parents told them that there will be gifts. They can't explain how the gifts got there, so the first way is to believe what their persons of trust told them at that time.
This is already a first step of an easy manipulation. The parents know how to sell the stories good enough and have an easy way to blackmail their kids (and tell them: If you have not a good behaviour, there won't be gifts from Santa Claus). When the kids hear that, they will
pay attention (at least for a moment).
3) When you really believe in something, there's a lot of motivation because of your thoughts. That's like a Placebo-Effect and a very positiv thing. You just can do a lot with your thoughts already. I believe in myself and what I do. For me that's enough.
By the way, here's the Video I talked about at top:
Stephen Hawking: Does God Exist?