>>531013128
Really, really depends on the race. See WoW has an understandable issue where they can't make a bunch of different effects to differentiate the classes depending on race choice, but in general -
>humans/dwarves/belves
Connection with Light via faith in their Oaths and the will to protect the innocent and slay the unholy. The 'Light' is basically the stand in for the Holy Trinity/God in their church system.
>draenei
They have a direct connection with the Naaru, they receive their Light power right from the 'source', as Naaru are basically angel equivalents in the WoW universe.
>tauren
They worship A'nshe the Sun god (who is related to Elune IIRC). Tauren have the weakest link to use the Light lore wise, as they live in a very shamanistic/druidic society. Basically their Paladins are Sun Druids.
>Zandalari
Used to get their power from Rezan, the Loa of Kings and blessed by the Light. He died in BFA, so now Zandalari paladins get their light from a few sources depending on the individual Zandalari. Either
>learning the more traditional Light usage from Belves in the Horde
>Carrying on the legacy of Rezan even after his death
>Belief in the divine right of kings/queens
>some combination of above
If you have played FFXIV, then you know how the Paladins in that game as basically holy protectors of the king/queen in ul'dah? That's basically Zandalari Paladins in this game.
Lore wise I don't think Tauren or Zandalari take any kind of traditional Paladin Oaths, so there's a lot of different options there.