There's no reason they should. I think they will continue to perform at least one of the functions they have always served. Here, I'm defining religion very broadly -- for me it is not just religion proper but all the subtle arts of the human species (music, philosophy, poetry, art, dance, etc). For me, that function is to mythologize (the initial processing methodology of the species) future natural wonders, make them coherent and understandable in one form until we can process and understand them clinically and scientifically.
The short answer to your question: In my opinion, no religion will or should become obsolete after 500 years. I'm not exactly a "believer" but I do not believe a world without religion would be a very constructive, happy, and more importantly productive place.