Big Question and Henry IV

So I didn't really notice any significant references to God or religion in Henry IV. The only places I saw references to God were in just casual slang such as "Splood" or "Zounds." And these mean very little, I likened them to someone saying "Oh my god" in modern day, it carries little meaning to it as far as I can tell. There are many mentions of sin and morality, also of honor, but none of them are indicated to have come directly from religious doctrine.

However, one thing I found fascinating in this place was the examination of the powers in the play. As someone pointed out, none of the characters are vastly dynamic, most of the play merely follows the action of the characters, but none of them learn much or change. I think it was Shakespeare's attempt to examine and possibly comment on the seemingly futile nature of royal feuds and war. Little is accomplished over the course of the play in the grand scheme of things.

Oedipus and big question

What is the role of God and religion in life? Are men subject to their Gods or is the perception of God shaped by men? What is the relationship between men and God? In what instances is religion used wrongly? What is the nature of God, wrathful or loving? Where is the line between God and religion?

My question is still really broad, I'm not entirely sure how narrow it needs to be. I don't want to paint myself into a corner for the rest of the year by choosing a question that only applies to some books.

In Oedipus, his fate is foretold by the prophesy by an oracle of a God. What his ultimate fate already known by his God, or did he condemn himself simply because he believed the prophesy? How does his use of religious references in his speeches affect his public image and overall power?