A.T. Robertson Commentary John 2:24

"But Jesus did not trust himself unto them, for that he knew all men," — John 2:24 (ASV)

But Jesus did not trust himself to them (αυτος δε Ιησους ουκ επιστευεν αυτον αυτοις). "But Jesus himself kept on refusing (negative imperfect) to trust himself to them." The double use of πιστευω here is shown by Ac 8:13 where Simon Magus "believed" (επιστευσεν) and was baptized, but was unsaved. He merely believed that he wanted what Philip had.

For that he knew all men (δια το αυτον γινωσκειν παντας). Causal use of δια and the accusative case of the articular infinitive το γινωσκειν (because of the knowing) with the object of the infinitive (παντας, all men) and the accusative of general reference (αυτον, as to himself).