It is particularly pernicious when it exists in a religious context. I'm sure you have read of all the times Jesus attacked the religious self-righteous in scripture. The reason it is so pernicious, is because it hides human ugliness behind a garb of righteousness, behind the name of God. It becomes apparent that these are the 'wolves in sheep's clothing' that Jesus pointed to, as well as those who claimed his name, only to be told, "I never knew you."
Be careful what you hear behind the mask of their words.
So you are saying that every Christian should think and believe exactly the same things in exactly the same ways without any differences in understandings, or practices? And that for them to not believe as you do, that is what makes them hypocritical?
Are you familiar with the entire 14th chapter of the book of Romans?
That is actually not true at all. You can see it even within Paul's writing at the time. People believed differently from each other back then, and there was no single one unifying belief, other than in Jesus as the Messiah. Paul had an argument with James and Peter over beliefs. It's in scripture, in Paul's own writings. Luke records it as well in Acts.
But beyond even that internal evidence, the discovery of early Christian texts has very clearly shown there never was a single theology in early Christianity. There were many competing views, and the one that became "orthodoxy" was just one of the many competing sects. There is a great deal of information available about this.
Yes. But unity of what? Ideas? Opinions? Beliefs? The entire 14th chapter of Romans has Paul explaining how different Christians believe different ways, and not to let that be our focus, but on Love. That is what he means about unity. We are united, in our differences through the Love of God. Right?
Something that may help you. Understand there is a difference between unity, and uniformity. Uniformity is sameness. Everything is the the same color. Unity on the other hand is about bringing all the disparate parts together, like a jigsaw puzzle. And once the pieces unite, a single image does appear, and that is the image of Love.
You mistake holding common beliefs as the same as genuine love.
Those who claim to be Christians, but spewing hateful rhetoric and division. Them.