How do you know what you believe is right and true?

No one knows for sure. You can always say this is what happened and we have the bible and ten commandments but where is the hard proof that its all real. I mean a crazy man could have just done all that and left it for us to find. Im not saying its all a lie but you cant proof it with science so i don't know. I guess its just the matter of taking a chance and believing in what you think is right.