As per title, do you think we should let religious beliefs have an influence in political decisions? If not, what basis should political decisions be made on?
well if you have religious people in power than obviously their beliefs will factor into their decisions
you can't ban religious people from power cause that would be discriminatory so the only answer is yes.
to clairify they still should not oppress the people with their beliefs (i.e banning gaymarriage, headscarfs w.e)
No. There are countless different religions that all believe they have the "truth." There is no reason to give one religion the power of having something to say in politics. That would also be discrediting the thousands of other religions.
Not at all not everyone follows the same religion, and religion often makes no sense. Ataturk was such a hero for secularizing Turkey in the last century, removing every single religious hint from the constitution