Aristotle regards the priority of actuality over potentiality to be one of his most important innovations. He regards it as a necessary condition for anything being intelligible. Along with the primacy of the good and that-for-the-sake-of-which in explanation, it is also central to his way of arguing for a first cause.
The Western tradition generally did not follow Aristotle on these points. Arabic, Hebrew, and Latin monotheisms have most often treated God as an absolute power, seeking to put unlimited omnipotence first in the order of explanation, before goodness. Christians were happy to criticize occasionalism in Islam, but theologians like Duns Scotus and William of Ockham defended an extreme sort of theological voluntarism, which was taken up again by Descartes. In the 19th century, Kierkegaard valorized Abraham’s willingness to sacrifice his son as unconditional obedience to God, claiming that faith should take precedence over ethics generally. In the 20th century, Sartre defended unconditional free will for humans, while asserting a militant atheism and the absurdity of existence. His currently influential follower Alain Badiou goes even further. He bluntly says that concern for ethics is a waste of time, and that dialogue and democracy are a scam — not just in particular cases, but in general.
Mainstream views of religion have always insisted that the absolute power is also absolutely good, but have been unable to show why or how this is the case. This has opened the door to simplistic but unanswerable arguments that the facts of the world cannot be reconciled with claims that it is governed by a good absolute power.
Instead of sacrificing ethics and the good on either religious or secular grounds, we should put them first. Leibniz argues that an emphasis on the absolute power or arbitrary will of God is bad theology, and effectively makes God into the kind of tyrant that Plato denounced (see also Euthyphro; Arbitrariness, Inflation).
Aristotle’s first cause doesn’t govern the facts of the world. It is the world’s normative compass. It is the pure good and pure fulfillment that all things seek, according to their natures and insofar as they are capable. Or as Hegel might say, it is pure Idea.
The priority of actuality is a priority of the good and of normativity. For Aristotle, we shouldn’t call something “actual” just because it exists or is the case. Rather, something is actual when it is the case that it is fulfilling its potential, as it “ought” to do.
It is not a matter of pure moralism either though. Actuality does involve an element of being the case; it is just not reducible to that. What is true also matters quite a lot in the determination of what is right, even though it is not all that matters. Every particular good is interdependent with particular truth. That is why Aristotle seems to make the understanding of causes into one of the most important elements of virtue, while at the same time cautioning us that ethics is not a matter of exact knowledge.
We are looking for a kind of mean here. What is true matters for what is right, but what is right also matters for what is true. Truth is not reducible to a matter of neutral fact. There can be no truth without intelligibility, and there can be no intelligibility without taking normative considerations into account in interpretation.