The first reason why brethren are often on different pages has to do with variations in individual personality. Some folks just don't click with other folks. They value things differently. Some are talkative and some are quiet. Some are bold to get in your business while others are very private. There are probably some Christians to which we naturally gravitate. There are also probably some Christians with whom we might struggle to have a normal conversation.
The second reason why brethren don't get along has to do with an individual's regard for their own opinion. Some Christian did something they didn't like. Perhaps a brother or sister in Christ hurt their feelings. Or perhaps they are too prideful to admit that their attitude about a particular situation or person is wrong. A lack of Christian behavior over one issue may lead to lack of respect in another. We stop being genuinely friendly. We tend not to trust one another. We hear gossip about a situation that has been elevated to a place it should have never been in the first place. Before you know it, we are so far away from some brethren that we don't even want to see them or hear about them at all.
Ralph Waldo Emerson once wrote, "The only sin which we never forgive in each other is the difference of opinion." William Blake once said, "The man who never alters his opinion is like standing water, and breeds reptiles of the mind."
It is tragic when even strong, faithful Christians don't get along. I have seen this in every congregation in which I have been a member. At the end of the day, this phenomenon still leaves me asking, "Why?"
Life is too short and eternity is too long for us not to make every effort we can to resolve our differences with others. The church is too precious and our relationships are too meaningful for us to continue to have too much pride to change our hearts and minds.
Be of the same mind toward one another; do not be haughty in mind, but associate with the lowly. Do not be wise in your own estimation. ~ Romans 12:16