A claim becomes more trustworthy when it survives attempts to disprove it.

A claim that nobody has tried to break tells you very little. Its strength comes from the attacks it has withstood: the alternative explanations ruled out, the contrary evidence examined and found not to hold. Support gathered without any attempt at refutation can be assembled for almost any position, which is why it counts for so little.

When something matters, spend some of your effort trying to knock it down rather than building it up. Ask who disagrees and what their best case is. A belief that has been through that comes out with a different quality entirely, and you will know why you hold it.