Eventually, it all comes down to your basic presuppositions

Everybody believes something, and they have a good reason for doing it.

 At least, it seems good to them. In reality, nearly all beliefs are based on other beliefs. The only exceptions are those things that are the basis of everything else. I call them basic presuppositions, though I'm sure some neuroscientist, philosopher, or psychologist has probably come up with something better. That's  all I have, though.

 They're basic because they're what everything else is predicated on, while they aren't predicated on anything else. They're presuppositions because we believe them without evidence. Not in spite of evidence, but not because of evidence either. Evidence doesn't even come into it.

I'd like to say that my basic presupposition has to do with the reality of God or with his eternal love or something pious like that. I certainly believe in those things like that, but there's something even more basic than those.

I have two that very seldom overlap but which between them cover everything in my life: the Bible is true, and my wife is smarter than I am. I believe in the first just because I don't have any other way of learning about him, and in the second because though our IQs almost identical, she's much wiser and harder-working than I am.