Is establishing proof against people through knowledge impermissible, such that it is better to leave them in their ignorance so that proof is not established against them?

First, excusing ignorance is an issue subject to scholarly interpretation and is a matter of disagreement among scholars.

Second, no scholar who believes in excusing ignorance advocates leaving the ignorant without invitation (to Islam) or education. This is due to the obligation of spreading the religion, teaching the ignorant, and establishing the proof against them.

Third, an ignorant person who finds someone to teach them but neglects to learn is sinful for abandoning what is obligatory upon them to learn, and they are not excused.