Sometimes, hope is unreasonable.
What do you do with an unreasonable person? Proverbs 25 puts it this way. “Like a broken tooth or a lame foot is reliance on the unfaithful...” Could they change? Sure, but until then it’s time to organize your life without them. This needs a lot of prayer. Say it’s an ex who won’t parent their own kids or someone who loves their addiction more than you. Not relying on them is painful and tragic but not as painful as continually chewing on a broken tooth. Trust God and trust the person to God.