Make it a Bard who wanted to be a Cleric but was indecisive about it and couldn't decide which Deity to worship, so he "worships" all of them. Just in case. Whenever he successfully casts Bard spells or rolls for a performance check, he praises a random deity. Has a whole keyring of talismans and holy symbols to pick from as needed. Stack as many proficiency bonuses on deception and persuasion as possible and convince the whole world he really is a Cleric.