God did not divide Christians. In spirit, we are one and we are complete. However, in soul, especially the mind, we come to Christ with all kinds of preconceived ideas and notions that are not of God. That's why we need the renewing of the mind. We have new hearts but old minds.
There are ministry gifts to the Church - apostles, prophets, evangelists, pastors and teachers. Regrettably, few acknowledge these gifts except for pastor and evangelist. The purpose of these ministries is to serve the Church - that's what "ministry" means.
The purpose is found in Ephesians 4:
12to equip the saints for works of ministry and to build up the body of Christ, 13
until we all reach unity in the faith and in the knowledge of the Son of God, as we mature to the full measure of the stature of Christ. 14Then we will no longer be infants, tossed about by the waves and carried around by every wind of teaching and by the clever cunning of men in their deceitful scheming.…
The Reformation achieved a great deal. However, it has not yet rid the church of some false doctrines and human traditions. This must happen eventually. Until then, Christians are bound to have differences of opinion. Add a lashing of ego and a dash of religiosity and you get the kind of discourse you see here at times. Children fight. Some people need to grow up.