I like the idea of it but from my own point of view the reason I wouldn't ascribe to humanism is because I don't feel I (or humans I guess) have enough knowledge and foresight to know what is ultimately best, we have made some huge mistakes, so I trust in a higher power.
There is a branch of Humanism called Christian Humanism. It is the belief that human freedom and individualism are intrinsic natural parts of, or are at least compatible with, Christian doctrine and practice. It is a philosophical union of Christian and humanist principles. So it is possible to combine both of them.

However, the word "Humanist" in it's single form rejects this.