There are forum sections for all of the above subjects on this website.
What are the specifics of what you want to discuss? For example, do you want to discuss religion or debate about it? Which specific aspects of religion do you want to talk about?
The same goes for politics; we have multiple political forum sections, so I'd have to know which topics you wanted to discuss to recommend you a forum section to post in.
Sorry if this sounds pedantic, but I'd have to know some details to give you an accurate answer as much as possible.
As for sports, this is the only section we have for sports-related topics: