"A truth that's told with bad intent/Beats all the lies you can invent."
William Blake (1757-1827), Auguries of Innocence.
Blake can be puzzling. I think I get his drift: don't use good things with bad intent. I often emphasize in class the teaching that we cannot use bad means for good ends. Blake reminds me to also recall that you can't use good means or things for bad ends.
Here is an example. I recall someone trying to correct a speaker in public in an unnecessarily blunt and flippant way. It turned out that the attempted correction was superficial in nature and in fact was off-base. The "corrector" used something technically true to contradict the significantly true message of the speaker. We see that often: using something true in a Pickwickian sense to overthrow a much more significant truth. Practical lesson: Make public corrections kindly and with some modesty--you may turn out to be wrong when more research is done. Even better make corrections privately. Most Important Lesson: Do not use technicalities to fight a bigger truth, or else you may end up inventing a lie.
(By the way, the obligatory disclaimer for pharisees: I do not agree with the religious or marital views usually attached to Blake.)