Here's a take on that from the think tank Ekklesia that's worth a read. A short snip:
Part of the issue here is that it is arguably more correct to say that there is no such thing as humanism but rather humanisms. Philosophies as different as Marxism, existentialism, pragmatism and Christianity itself have all claimed to be a humanism.
The writer, Mark Vernon, also says that he fears Humanism will be taught as opposition to other systems.
"[T]he interest in, and flourishing of, humanism is closely tied to its historic and present diversity," he concludes. "Both will be eroded if its relationship with religion is presented as a zero-sum game."