You fail to comprehend the difference between belief and religion. A statement of belief about a deity, presented as fact, is religion. That of course doesn't mean that it isn't stupid.
I have no such faith, and am not defending the notion. I am simply pointing out that because of the subject matter, these kind of statements are indeed religion. Stated the way you have couched your statements above, i.e. "I am pretty sure," "probably right," etc., it is another matter.
This is not simply another unknown; it is on the minds of many humans, as it deals with two questions we do not have answers for - where did we come from, and what happens after we die.
Science can not yet adequately explain the first; whatever caused the big bang, the origin of what matter went 'bang', etc. Nothing can explain the second. I have my own set of beliefs, pretty much like yours, with respect to this. But to make a statement concerning the existence of 'god' is religion, purely.
"I'm sure we all agree that we ought to love one another and I know there are people in the world that do not love their fellow human beings and I hate people like that." -- Tom Lehrer