Christians Must NOT Punish Moral Failings.

We have absolutely no right to “punish” people for moral failings (c.f., Matt 5:7; 7:1).  ”Punish” comes from the Latin root, “punire”  meaning, “to inflict pain.”  It is simply not our place to inflict more pain on a guilty person than they are already experiencing in their guilt. (ED: Or lack of it!)

That said, we do have a right, and even an obligation rooted in love (defined as the commitment to work for the good of others) and justice (defined as the virtue that ensure that each person receives what is rightfully theirs), to hold people accountable to themselves (if their moral failing hurts them) and/or to us (if their moral failing has damaged us or our relationship.
But holding someone accountable–in the classical Christian context–simply means seeing that the person is committed to healing the damage caused by their actions and, ideally, giving them the skills to not make the same mistake again.  Dr Greg.