To sum it up: It [the inscrutable One] is the life of the living, the Being of beings, It is the Source and the Cause of all existence, and therefore Itself transcending existence. It alone could give an authoritative account of what It really is.
A Patristic Treasury: Early Church Wisdom for Today, edited by James R. Payton, Jr
God
We cannot know God in His nature, since this is unknowable and is beyond the reach of mind and reason.
We must not dare to resort to words or conceptions concerning that hidden Divinity which transcends being, apart from what the sacred Scriptures have divinely revealed.
Since the way of negation [when talking of God] appears to be more suitable to the realm of the divine, and since positive affirmations are always unfitting to the hiddenness of the inexpressible, and manifestation through dissimilarities is more correctly to be applied to the invisible.
What might the first centuries post-Constantine looked like for the Church if only negative statements were used to describe God and the Trinity? Not getting divided over what God is, but instead focusing only on what He is not.
Those who continued to believe what the Church has concluded that God is not would have left – just as happened after a few of the early Church councils. However, we would have avoided splits over disagreements about the words used to describe what God is.
Likely we would have had fewer splits.
The divine Mind, therefore, takes in all things in a total knowledge which is transcendent. Because It is the Cause of all things, It has foreknowledge of everything.
The idea of God’s foreknowledge is a stumbling block for some. I have heard it described in a way that might be helpful: it demonstrates God’s grace and favor; God’s intimate knowledge of a person.
Immutability
Even if disorder and confusion should undermine the most divine ordinances and regulations, that still gives no right, even on God’s behalf, to overturn the order which God Himself has established. God is not divided against Himself.
God does not change, nor do His ordinances. Man’s cultural, social, and intellectual evolutions and deviations don’t change God – as if God’s laws applied to the first century, but we know better or know more. These changes just mean we are wrong, that we are putting ourselves in the place of God.
Prayer
We must begin with prayer before everything we do, but especially when we are about to talk of God.
Teaching
Those who do not know must be taught, not punished. We do not hit the blind. We lead them by the hand.
Divinization
Divinization consists of being as much as possible like and in union with God.
He gave us a most perfect share of His nature by completely taking on our own, and in this way He made it possible for us to enter into communion with Himself and with divine reality.
The Christian life is so much more than finding the right formula to avoid hell and enter heaven.
Biographies / Sources
A Greek speaking Christian penned several documents under the name Dionysius the Areopagite, at the latest by the early sixth century.
Acts 17: 32 And when they heard of the resurrection of the dead, some mocked, while others said, “We will hear you again on this matter.” 33 So Paul departed from among them. 34 However, some men joined him and believed, among them Dionysius the Areopagite, a woman named Damaris, and others with them.
Initially, these words were accepted as written by the apostle Paul’s traveling companion. Doubts about the authorship would arise periodically, and by the sixteenth century were widespread.
"Since the way of negation..."
I do wish that the Church had a more humble view of what God is. But maybe if it didn't have such a rigid view, the Church would have been overrun by heresy. There are some positive things we must say about God based on Holy Scripture, but I think there is plenty of room for mystery and disagreement.
One example here is the Filioque controversy. Roman Catholics believe that the Holy Spirit proceeds from the the Father and the Son, and the Eastern Orthodox believe the Holy Spirit only proceeds from the Father. I think the historical case is on the Orthodox side, since Rome had to change this formulation (in response to heresy) about 1,000 years after the birth of Christ. But I think the Catholics have a better theological case. Either way, does it really matter? Can we not just say that the interrelationship between the Three Persons of the Holy Trinity is something of a mystery?
"Those who do not know must be taught, not punished. We do not hit the blind. We lead them by the hand."
But what if in addition to them not knowing, they think they know everything and will use everything at their disposal, including political force, to marginalize, malign, and destroy the truth as completely as they are able to? Those with willing hearts and minds should be treated with every bit of decency and compassion in the attempt to bring them into the fold. For those "cities" that callously reject and spit on Christ and His Gospel?
"Amen I say to you, it shall be more tolerable for the land of Sodom and Gomorrha in the day of judgment, than for that city." - Matthew 10:15