Yes, we all must acknowledge humans create religions. That is a given. If you are a christian, then you acknowlege that thousands of religions (except yours), is made by man to explain things (volanoes, lightening, life, univerise, etc.)
If you are Muslem, the same applies, but now Islam in the one exception.
I think if I was born 1000 years ago, and didn't have any knowledge of the world outside of my community or country, I might believe whatever religion was followed in my society at that time.
But, now that we know of all the other countries, populations and communities, each with their own religions, then we know things for sure:
1. Humans create religions
2. Humans follow religions that are created by humans.
With these undeniable facts, how do the religious justify their beliefs?