"Sometimes relationships grow stronger through conflict. But other times relationships end. Because I can’t control the other person, I must keep focusing on the good God is working out in me through this and leave the outcome with Him." Lysa TerKeurst
Bringing God honor and giving a testimony to others should be the goal in all of our relationships. In a broken relationship, if the other person doesn't want to change or work it out, that is the other person's issue. God will reward each individual for what is in their hearts. One is not contingent on the other.
Broken relationships can be healed, but to make them work, both sides need to admit they are displeasing the Lord, hurting each other, humbly accept responsibility, surrender the relationship to the Lord, commit to behaving in a godly fashion by trying to understand each other, and then make necessary changes in ways that bring Him glory. All we can do is examine our own hearts and determine to do God's will as far as it is up to us.
(If some of that does not translate well, please contact me.)
I Peter 3:8 Finally, all of you, be like-minded, be sympathetic, love one another, be compassionate and humble.
Hebrews 12:14 If it be possible, as much as lieth in you, live peaceably with all men.