Boiling things down, the reason for division, hurt and the like in the Church is simply a departure from love. The fighting and refusal to be truly reconciled to one another started with lust and carried on with pride.
James 4:1-2 What is the source of quarrels and conflicts among you? Is not the source your pleasures that wage war in your members? You lust and do not have; so you commit murder. You are envious and cannot obtain; so you fight and quarrel. You do not have because you do not ask (read also verses 3-12).
The refusal to do things God’s way reveals a lack of true belief. A person’s need to be right, and fear of being wrong in the eyes of others exposes one’s failing to believe his or her identity as a child of God. It also reveals immaturity. When a group of people is filled with individuals who are so wrapped up in themselves, it has no ability to sustain cohesiveness. As long as we try to unify the Body of Christ on our terms, it will never become one Body. Why do you suppose the Bible says, “Endeavouring to keep the unity of the Spirit in the bond of peace” (Ephesians 4:3)? Our unity requires Holy Spirit; not our theology! Without Him, we will not properly love one another, which is a requirement for unity. Remember, Galatians 5:22 shows that love is part of the fruit of the Spirit, and that means love (AGAPE) is derived from Him. That dovetails off of what Jesus said in the book of John.
John 17:22-23,26 “The glory which You have given Me I have given to them, that they may be one, just as We are one; I in them and You in Me, that they may be perfected in unity, so that the world may know that You sent Me, and loved them, even as You have loved Me. I have made Your name known to them, and will make it known, so that the love with which You loved Me may be in them, and I in them (read entire for full context).”
Notice, Jesus gave us His glory and His love. Why? So we would be one, and that the world may know Father sent Him. Our lack of unity hinders the Gospel. By definition, love (AGAPE) takes joy in the recipient for the recipient’s sake alone. That kind of love is not selfish (Read 1 Corinthians 13 for more details). It is not looking for the Return On Investment (ROI). Not only that, it eradicates fear. If we truly love one another, we won’t have to be afraid of each other. In fact, we’ll be free to celebrate every brother and sister in Christ.
Hurtful religious traditions of men crept in when love lost the focal point. In the name of being holy, people became more concerned about one another’s behavior than their welfare. They chose to judge and shun others who may have fallen, instead of loving them and seeking their restoration. Their own reputation became more important than the love of God. They became pretenders, actors, or more clearly, hypocrites. One of the fastest ways to become a hypocrite is to become self-absorbed and vacate love; not necessarily in that order. Love has compassion for the sinner and the backslider. When you read Exodus through Deuteronomy, you discover that Moses fell on his face before God to intercede for a people whom God was prepared to destroy. The children of Israel rebelled; in fact, they slandered God and Moses. Even still, Moses feared the Lord, and feared for the people. Yet, here we are with the love of God dwelling in us through Holy Spirit, and how concerned are we really for our brothers and sisters, let alone sinners? Who is our First Love? Think about this: Love never requires repentance! By walking in love, we actually avoid sin.