Actually, many religions are just manifestations of the same thing. I've never thought that someone who practices Wicca is wrong or right compared to a Christian, they just have different means to reach the same end, which is spiritual fulfillment. I also don't think it's any surprise that man seeks to name the divine. For some, it's reassuring, for others it gives them a place to release their guilt. Life is messy and difficult, and the thought of a higher power eases the way. But yes, that's all man-made constructs.
I've said it a few time already and maybe I'm just not explaining it well, but there is a difference between religion and the belief in a higher power (God, Allah, Mother Earth, call it what you will.) You do not need to subscribe to a certain methodology to believe that life is a gift and the human spirit is greater than we can define. There will never be a good enough explanation for love and reason that will stop me from seeing it as supernatural in nature.