Well the thing is, to be able to learn if you can trust someone...you have to trust them. Then they either show themselves trustworthy, or not.
if you learn what the Creator's Word says about man/men, you won't trust anyone.(trust only Yhvh in Yeshua; test all other).
John 2:24 from various>>>
John 2:23-25Young's Literal Translation (YLT)
23 And as he was in Jerusalem, in the passover, in the feast, many believed in his name, beholding his signs that he was doing;
24 and Jesus himself was not trusting himself to them, because of his knowing all [men],
25 and because he had no need that any should testify concerning man, for he himself was knowing what was in man.
Aramaic Bible in Plain English
But Yeshua did not entrust himself to them, because he knew all men,
American King James Version
But Jesus did not commit himself to them, because he knew all men,
American Standard Version
But Jesus did not trust himself unto them, for that he knew all men,
Douay-Rheims Bible
But Jesus did not trust himself unto them, for that he knew all men,