What determines what you "believe" in?

What I believe IS the case? Evidence.
What I believe OUGHT to be the case? Reason.

The truth, I want to believe in truth.

One's actions (not what one says) show what one believes in.

Depends on how plausible the subject is and how much evidence backs it.

Let me break it down for you:

Suppose you tell me you have a green car. I'm going to take you at your word because there are millions of green cars, I've seen thousands personally and actually own one myself, and the fact that you have a car that is green is completely reasonable.

Suppose you tell my your green car was once owned by Ronald Reagan. I might do a quick search on the internet to confirm that, but I would not necessarily dismiss your claim outright because I know Ronald Reagan did exist (I met him once) and it is entirely possible that he at one time had a green car.

Suppose you tell me that your green car once owned by Ronald Reagan is possessed by his ghost. Now I'm going to demand some real evidence or simply not believe you. Extraordinary claims need extraordinary evidence.

Whether it is a proven belief by the Bible itself. Using the Bible to interpret itself, making sure what it really says is what we thought it might say.

From time to time, it happens we find new evidence we were wrong in a point. Not the entire matter, just a few details. This might shock you but at one time, Jehovah's Witnesses celebrated holidays. Then 2 Corinthians 6:14-17 brought out Jehovah commands, demands, exclusive devotion with no paganism allowed. Finishing in verse 17 to, " Seperate yourselves and get away from them. Quit touching the unclean thing. THEN I WILL TAKE YOU IN." Notice Jehovah God will not accept anyone worshiping him unless they are first getting rid of pagan false religions.

So when we saw this was true about ALL holidays, we stopped. All holidays have been based in paganism. It makes no difference if it to "honor" God or Christ. The Bible never stuttered. No paganism in pure worship if Jehovah God. That is what Truth us.

I like evidence....so it's how I perceive that evidence.
I love l8gic...for me, must make sense...it dies...it's how
I see it.
Genetics, epigenetics, how God leads or does not lead.

I think it depends on what matters to you. Just look at the word: believe. To be live. To be lie. To live a lie is many times the case. Fairy tales are great and they color our world. But for the serious seeker the truth and the journey in search for truth should be all that matters.

In no particular order:

Does it matter?

How does it fit with the rest of what I know to be true?

How much will believing it cost me?

How credible is the source?

And finally-- what do people I respect think?

We have the bible and common sense think about why did God destroy people in the past? Noah and the flood tells us because the people were so violent. Sodom and Gamorah for homosexuality. Baal worshippers for killing babies. They had temple prostitutes and burned up new borns to false Gods so killing others is a definite no no.

your superstitious mind.

the truth, science and nature

The amount of available evidence

My moral code. I believe in having good morals and having a good christian foundation.