Matter of personal opinion. Personally, I choose not to believe in a higher power until there is definitive proof of one. It's known as agnosticism. But the point of religion is faith, faith that there is a higher power. It's a matter of personal opinion.
Their is proof that the text of the bible holds truth. All the evidence lies in jerusalem and around those parts...but God isn't about proof. He's about faith. Once you accept him into your heart he steers the wheel and its the most beautiful journey.
Up to you. In essence a persons beliefs should not be steered by those around them, but by what they choose to accept and put faith in. Dont go asking if god is there, ask yourself if you believe he is there.
When you say god do you mean Zeus or Inti (Inca sun god). Either way no god exists. The idea of god came about because people where unable to explain the wonders around them. They figured there must be a higher power. Previously people believed in multiple gods, thus there was a lot more freedom of religion since you were free to believe in whatever god you liked. Now, with monotheism, everyone believes their god is the right one and god forbid you should challenge them. Think about it. if I tell you "have faith - unicorns exist!" does it mean that unicorns really exist?