"Homo" means "same" or "unison". HOMOgeneous means "uniform" or "same". HOMOsexual means "attracted to the same sex". HOMOnyms are words that share the same spelling or pronunciation but have different meanings.
"Homo religiosus" refers to the idea that human existence is inherently religious. You can think of it like people are homogeneous in that they are all religious. It is related to the evolution of religion in the sense that every culture in the history of Earth has had some form of religion or set of beliefs.