Christian Theology

Christian Theology draws on Greek metaphysics, particularly the works of Aristotle, Plato, and Plotinus. Plotinus in particular is influential in late Roman paganism, Christianity, Judaism, and Islam and his teaching echoes Eastern philosophy (this may have something to do with the time Plotinus spent  studying with Indian and Persian intellectuals). Anti-Christians mockingly summarize the Christian worldview as "a bearded father figure created the world and now commands us to give money to his church". That is indeed the picture we get from the oldest Jewish scriptures, which the Christians inherited. But it does not do justice to the beauty and the elegance of mature Christian thought.

No Christian thinker believes he can prove every plank of Christian Theology. Aquinas thought he could prove part of it, but not all of it. Rather, the complete worldview represents a "best guess" as to the nature of the universe according to logic, observation, shared experience, and introspection. In the 20th century, the mathematician Kurt Goedel proved that there are true things that we cannot prove in mathematics, so the unprovability of Christianity is not as big of a mark against it as some would believe.

Theologians would point out that those who do not believe in the Christian worldview often act as if they believe in something like it. All productive, non-suicidal people need an answer for why they get out of bed in the morning, why they strive to build and create. Many people seem to believe in transcendental, eternal ideals which are good in their own right that drive them and guide them. The contour of such a worldview belongs to the same genre as Christianity. The secular Humanists and Utilitarians are not so different.

It or a philosophy like it is necessary for a productive, happy human life. Wherever you find your meaning, whatever ideals you put your faith in, they are necessary. This is less true for people born in happy circumstances, and more true for those of us who have had to battle through life.

This is my paraphrase of the Thomist/neo-platonist idea of Christian Theology:

God is simple, not complex. God is good. He is not good like a human is good. That is, he is not good because he has good qualities or does good things. Rather, he is equivalent to the ideal of goodness. All other ideals which are related to goodness also are derived from him (e.g. Plato tells us that beauty is a kind of goodness). 

Badness does not exist. It is an absence of goodness, a form made of negative space. The bad is the lack of God. 

God does not exist before the world but rather outside the world. He is not in time, because he made time. As time stops at a gravitational singularity, so time did not exist before God made it. God is simple, so the world before time is one of simple, unchanging perfect goodness. 

Time begins with God's first creation, the son or the word. God's thought of himself give rise to an image of himself, and that image is the word. With creation, complexity enters into the universe and with complexity, change. With change we get an arrow of time. 

God created matter and material beings in perfect goodness. The conscious beings he created lived in joy, and he saw that it was good. But he saw that it would be better if they had free will, so they had the capability to choose not-God and not-Joy. They did, which is why there is so much badness on the Earth today. But God put in a safety mechanism to redeem mankind from badness and lead them back to him.

In life, when we choose goodness we become more godly and we experience a tiny piece of the joy of God. As reflections of God, goodness is what we were designed for. When we dwell in goodness we fulfill our purpose.

Just as the mathematics of the circle point us to the existence of the ideal, immaterial perfect circle, so does the existence of goodness point us to the existence of the perfect goodness in God. In fact, all ideal things are emmanations either from him or from not-him. Mathematical ideals are also a reflection of him.

According to Wikipedia the Thomist view of god is thus:

God is the sole being whose existence is the same as His essence: "what subsists in God is His existence." (Hence why God names himself "I Am that I Am" in Exodus 3:14.) 

Further, He is goodness itself, perfect, infinite, omnipotent, omniscient, happiness itself, knowledge itself, love itself, omnipresent, immutable, and eternal. Summing up these properties, Thomas offers the term actus purus (Latin: "pure actuality").

Thomas held that not only does God have knowledge of everything, but that God has "the most perfect knowledge," and that it is also true to say that God "is" his understanding.

Aquinas also understands God as the transcendent cause of the universe, the "first cause of all things, exceeding all things caused by him," the source of all creaturely being and the cause of every other cause. Consequently, God's causality is not like the causality of any other causes (all other causes are "secondary causes"), because he is the transcendent source of all being, causing and sustaining every other existing thing at every instant. Consequently, God's causality is never in competition with the causality of creatures; rather, God even causes some things through the causality of creatures.