instructing those that oppose themselves: sounds like people working against their own interests, self-sabotaging

2 Timothy 2:25 tells Timothy to be gentle "in meekness instructing those that oppose themselves." A modern reader hears "oppose themselves" as reflexive in the self-defeating sense: people who fight their own interests. But the underlying Greek word is a middle-voice verb that simply means "to be adverse, to be an opponent." The KJV's "themselves" is just carrying over that Greek middle-voice grammar into English; it isn't claiming these people are self-contradictory. Paul is talking about opponents of the truth whom Timothy is to correct with patience, not people undermining themselves.