"what causes fights and quarrels among you?...you desire but do not have..you do not have because you do not ask God" (James 4:1-2 NIV).
The first biblical step towards restoring a relationship is to talk to God before talking to the fellow.
Discuss the problem with God in prayer and meditation of the word. If you will pray about the conflict first instead of gossiping to a friend, you will often discover that God changes your heart or he changes the other person without your help.
All your relationship would go more smoothly if you would just pray more about them. As David did with psalms, use prayer to ventilate vertically. Tell God your frustrations. Cry out to Him. He's never surprised or upset by your anger, hurt, insecurity or any other emotions. So tell him exactly how you feel.
Most conflict is rooted in unmet needs, and some of these needs can only be met by God. when you expect anyone...a friend, spouse, pastor, or a family member to meet a need that only God can fulfill, you are settling yourself for disappointment and bitterness.
The Apostle James, noted that many of our conflicts are caused by prayerlessness as earlier quoted.
Instead of looking to God, we look to others to make us happy and then get angry when they fail us.
Trust in the lord with all your heart and lean not on your own insights and pray without ceasing...with that all you ever needed will be in abundance.