HOW would you accomplish this? Would you have a Constitutional amendment that said, "Any candidate for office must claim that they have faith in God"?????? WHAT purpose would that serve, EXCEPT, maybe, to assure that many "politicians" would be willing to lie in order to be candidates in an election.
The idea, on its surface, is pretty far-fetched. From MY point of view, I find it not only unthinkable, but terribly offensive and undesireable, since it smacks of "theocracy"... and that is EXACTLY one criterion that I do NOT want to have in my country's political arena!!!!!!!