What does it mean to "Believe"?

I was inspired by a recent conversation with friends to think about this again. The conversation was specifically about religious beliefs, but I think it applies to all belief. The recent death of my friend Tim also caused me to think about this more, not in the "what happens when I die" way that you might think, rather because of the lengthy conversations and debates that I enjoyed with Tim and Niki during my first two years of college. At that time, I was very obsessed with being able to explain exactly what I "believed", knowing exactly what I "believed" and being able to logically explain what I "believed".

In the last 10 years I have changed (in many ways!). One significant change is that I'm not as hung up on this as I used to be. I wouldn't say that I have any more, or any less, questions than I had when I was six years old. Some of my questions have changed, but the total number has not grown more or less. The change is that I decided to move beyond nailing down the minutia of my "beliefs" and instead focus on trying to figure out what they mean, or how they should impact my life. But is this copping out? What does it mean to believe something, anyway?

Does it mean to be logically certain about something based on a set of facts? (Such as believing in gravity because every time I drop something it falls to the ground? Or believing that I need to eat while hiking so that my body has enough energy to continue?)

Does it mean to act on something? (Such as getting married because one believes the other loves them and will stay with them forever? This is different from the above because there's no "proof" only evidence that one is making a good decision)

Does it mean to decide to believe something? Does deciding to believe something make it "true"? Is this sometimes the case?

There are probably many more definitions. More questions than answers (always), but I really hope it's not limited to the first definition.

The dictionary's first definition of belief is "to have confidence in the truth, the existence, or the reliability of something, although without absolute proof that one is right in doing so". I love this! This is hopeful!

I want to be freed from trying to "prove" things. Proving things is exhausting and I'm not convinced it's very productive.