A paladin's power depends a lot on the god he chooses to dedicate himself to, so it depends a lot on the history of the game and the pantheon, but let's assume the paladin is a devotee of some luminous god or something like that it would be natural for him to have spells of healing, now let's say he has devotion to a god of war, so he would have more attack skills.
It would be interesting to see the paladin perform miracles, see him engulf his sword with divine energy to increase damage, or see the paladin summon spiritual armor that would increase his defense.