Giving the gift of grace doesn't guarantee a happy ending. Oh that it would! I remember when my daughter was in 1st grade. She and another young girl were sharing a computer when my daughter accidentally elbowed the other little girl. "I am so sorry," my daughter exclaimed, "Would you forgive me?" The other little girl, angry, said, "No!" My daughter was devastated.
Just because we do the right thing, doesn't mean we get the right ending. Such is life. In our relationships, we can give and give and give, and still, sometimes not win over the other person. That's not to say we shouldn't try. We should love as Jesus loved. We should give grace. But we shouldn't become doormats or co-dependent. Sometimes the most graceful thing to do is to walk away from a relationship. To continue to "love" and "give grace" from afar.
In Acts 15, the Apostle Paul and his ministry partner Barnabas have a disagreement. Neither is willing to relent, and so they go their separate ways. Both men of God, both spreading the Word of God. Yet, not together. Still, Paul speaks with esteem and affection about Barnabas in the epistles written after the event. He gives grace to Barnabas, even while choosing not to continue in ministry with him.
Outside of heaven, will we not have perfect relationships. We are not perfect people, and even if we are, we are around other non-perfect people. The only grace that never fails is God's. His grace saves, and never lets us down. We can show love and grace to others, but we must show ourselves that same love and grace. And that means sometimes choosing to walk away.