Why should I believe in what scientists say, but not what priests say?

To me, a lay person, there is no sure way to know that God exists or atoms exist. So why do I feel disbelief when the priests say something, anything, but profound relief when reading scientific books. Either way, I cannot test their hypotheses.

The thing is I do not have what the scientists have. They have good education, labs, finance, all kinds of resources necessary to reach their conclusion. And they have scientific principles and stick to those. Though I do not have what scientists have, in general I believe them because they stick to their principles and have nothing to gain from manipulating my thinking.

On the other hand, I have all the thing that the priests have. That means the brain, and only the brain. I use that tool, and it does not lead me to knowing God. Does that mean my brain is twisted and theirs are good? I think it’s much more likely that the case is the other way round.

Just a thought.