Bhagwan, Ishwar, Allah, Guru, Sai, Devta, Devi etc... are all the various name of GOD. Have faith in it, if not try to develop it.
Every people who don't have faith in the PARAMBRAHM might be having many reasons and every other person might be having his/ her own reasoning not to follow or having faith but I feel and thus suggest that no such explanation will remove or diminish the whole existance, presence, improtance & beliefs of the belivers of GOD.