Divine Power can be thought of as the mana that gods use.
This "mana" does not need any specific spell, only being limited by the amount of Divine Power possessed, the world where the God is and the priesthood of the God.
Thus, it is possible for Apollo to spend 10 God Power Points to create a lake in Naruto's world, but in a world of fire, this value would be increased several times over.
Another example of spending God Power is on offense.
Gods can use Divine Power to attack using whatever means they can think of, but if that means is related to their priesthood, the cost of Divine Power will be much less.
For example: Apollo can use 10 God Power Points to create a Fireball to blow up a mountain. But he would need 50 Divine Power Points to use a Lightning Magic to do the same damage.
To build Light Rings, Apollo spends 100 God Power Points.
This cost is high, as he needs to use gold in the construction of the ring, as it is a metal resistant to corrosion, thus increasing the longevity of the ring, and does not interfere with the small Mythril stone that absorbs sunlight and stores the magic that Apollo did to connect the ring to the sunlight server, plus of course, how much God Power he expends each time he programs this spell.
Any doubt about the Divine Power can be commented and if the question is relevant I will add it in this chapter.