Disagreements are one thing, and they agree they happen all the time, but I don't think they are the same thing as creating a separate denomination. A disagreement would be two parents arguing over how to spend the family budget. Creating a separate denomination would be a divorce that drags on forever in a fight over who gets custody of the children.

A more secular example of what a denomination would be, is a political party. And I think political parties have had the same effect on the country, as the nominations have had on Christianity.

Mostly I think it comes down to people believing they have an authority to dictate how others practice their religion. If you are not Baptist, you are going to hell. If you are not Catholic, we will convert your families by the sword. Whip you until you comply. Burn you at the stake if you do not confess.

Jesus made it very clear that your faith is a personal relationship between you and him. It is also an entirely voluntary thing. Nobody can force you to be one thing or to act a certain way.

For instance the example you linked, I do not agree with her interpretation of tongues, but I do not believe it is my place to tell her she is not allowed to do this. I would merely mention that the Bible describes the ability to speak in tongues as the ability to communicate the word of God to all people in a way they understand no matter what language they speak. It is more like a universal translator. If she chooses to heed my advice, wonderful! If she does not, I would hope she at least considers my words, but that is the end of the exchange. We move on as brothers and sisters in Christ.