I want a Cleric that has no powers that worships AO... Oh wait that's just a fighter
Unless there is something new in 5E.?.
Cleics are by definition powered by their gods.
You could be a paladin or religious fighter.
Well, there are some examples. As computer game player (not PnP) I know Fall from Grace (PST) and Zajive (NWN2) as clerics without god. Ember from WotR is a witch, but she is quite similar.
But those are all very special cases. Usually all clerics and paladins need a god for their powers.
I think a valor bard could be the best option to play a cleric without a god.
You walk around in medium armor, shield and martial weapons and you select only spells that are also on the cleric list.
Maybe you role play that your bard actually believes (s)he is a cleric.
Anyway, it would be very nice to have more gods and domains.
The PhB has a list of both, at least this we should get.
Prof. Dr. Dr. Mad S. Tist 
