Religion, generally, helps give people positive reasons for existing in ways that are beneficial to society.
Religion may be a tree with many branches but the problem is that each branch believes it is the TRUE branch. That is a valid belief or else the branch is wasting its time and energy. If it isn't the "true" branch it should be merging with that branch which IS the true one.
Therefor the need for argument. The necessity to determine whether one's religion is the true one or not. What a waste of time to find out you've been swimming to the farthest shore when there was one a lot closer.
Harmony will come, from arguing or otherwise, when we all come to the realization that ALL paths (Christian or otherwise) do lead to the Oneness of God. Some just take longer routes.
v Religion and church
1) The common purpose of religion is to aid the entity in its search for Truth.
2) Each entity's level of development and understanding is different.
3) It takes many different styles of religion to accommodate the growth needs of entities at various times.
4) The value of a religion can be judged by its operation and intended accomplishments.
5) Churches exist for the benefit of entities.
6) Churches are to religion what a bathtub is to water.
7) They allow the entity an opportunity to soak in the fellowship of like-minded entities.
8) Churches also allow an entity a method through which to share.
From my chosen path i stray,
Yet my God ne'er turns away;
For i have learned -- and understand,
That where God is -- is where i am!