This is a bad idea. There is a huge disconnect between what one person thinks and what another thinks, and it's only ten times worse when it's a DM and player. The DM has a play style and so does the player, and they won't always match. The DM might think more like a defensive background type and pick spells of that type, but the player might be more a front line combatant. And even if the DM tries to give a good ''mix'', it's still the ''mix the DM likes'', not the player.

Though I do love adding fluff and making clerics unique. And the way I do it in my game is the god can alter the spells cast by the cleric. The idea is simply the god watches any use of divine power, and judges. If the god agrees, the spell works and if not, the spell fails. Even more so if the spell is cast following the gods ethos, it will get some sort of boost, and if it goes against their ethos it will get a penalty. It's a great way to get a player to role play being a cleric of a unique god, and not a boring copy cleric that just does whatever.