what is the purpose of having "faith in humanity"?
its to build a small amount of trust in people, which is essential for healthy social function. also, its a reminder that good exists, and that not everything is always bad
if you think that's all there is, then you might as well just accept the crap in the world and do nothing. however, having faith and yourself and others is the key to change. there is tendencies for good and evil in everyone, and just expecting evil is all you will get