Is humanism the solution to division?

I’ve been reading the Humanist Manifesto I and II. In it, they say religions and creeds are divisive, and we should abandon them for that reason. We need to be united. It’s the only way we can solve our problems.

But don’t they see the inherent contradiction here? Humanism is a point of view. As such, it’s divisive. All worldviews are divisive for the simple reason that not everybody will share that worldview. Humanism is no exception. Whenever you assert a point of view, you divide yourself from people who disagree with you.

Even if your point of view is pluralistic, you’re going to cause division with people who are not pluralistic. There’s no escaping it.

The solution to division, according to the Humanist Manifesto II is that everybody abandon their religions and creeds and adopt humanism. It says, “We affirm a set of common principles that can serve as a basis for united action—positive principles relevant to the present human condition. They are a design for a secular society on a planetary scale” (p. 15).

Well obviously we’d all be united if we all adopted humanism. But then again, we’d be united if we all adopted Christianity, too. We’d be united no matter what we all adopted as long as we all adopted it. So to suggest that we should abandon religions and creeds because they are divisive, and we should adopt humanism instead, is just sloppy thinking. I’m surprised so many educated people signed this.