There’s nothing like a clear autumn day to get you thinking about God. So, with a hammock beneath me, a clear, blue sky above me, and the rustle of a gentle breeze through fallen leaves in my ears, I began to quietly contemplate how I would continue to summarize the talk I gave 2 weeks ago on God. You can find my first attempt (dealing with the existence of God) here if you missed it. In this installment, I’ll talk about the nature of God.
Jews, Christians and Muslims (and probably many other religions) believe in one God. Speaking through the prophet Isaiah, God reveals that “I am God; there is no other.” Catholics profess our faith in one God in the Nicene Creed: “I believe in one God, the Father almighty,” and many Christian faiths make similar professions. The existence of one God makes sense if you believe that the word “god” refers to a transcendent being that is the source and summit of all things. With that belief, you can’t have competing gods – a god of the sun, a god of the sea, etc. Having one god for this and one god for that necessarily means that no one god is the source and summit of all. Each god would necessarily be incomplete and, therefore, imperfect.
We also believe that God is one in nature, substance and essence. The great Jewish prayer says, “Hear O Israel, the Lord is God, the Lord is one.” (Deut.6:4) God, therefore, is unitary; God is unique. As the second century Christian author Tertullian said, “If God is not one, He is not God.” Why is that? Well, God is by nature perfectly simple – the source and summit of all things can’t be made up of competing parts. God cannot contradict himself. If he did, he wouldn't be perfect. So when we speak of God’s justice, God’s love, God’s wrath or God’s mercy, we’re speaking about the same thing – in God. In God, these qualities can’t contradict each other. So for those who struggle with how God can forgive people who commit horrible crimes, remember that God’s justice, God’s mercy, God’s love and any other quality of God that you can think of are one and the same thing in God.
God’s simplicity also helps us understand that God is the fullness of being. “What God’s simplicity entails, in a word, is that the divine is not any sort of being, any particular instance of being, but is rather the sheer act of existing itself. God is not this or that; God simply is.” God told us as much when he revealed his name to Moses: In the Book of Exodus, after God asks Moses to deliver his people from slavery in Egypt, Moses asks God for his name so Moses can tell the Israelites who sent him to them. God responded with the word “YHWH,” which means, “I am who am,” or “I will be who will be.” (Exodus 3: 13-15) The divine name, therefore, expresses God’s fundamental nature as BEING, past, present, future, eternal. God is “the fullness of Being and every perfection, without origin and without end.”
Now we have to ask ourselves what it means for God to be eternal – without origin and without end. Well, eternity is the ever present now. There is no time in eternity. That means there is no past and no future. It’s just now. Because God is being itself, God is equally present to the past, the present and the future. In other words, the past, the present and the future are one in God. And because God is timeless, i.e., eternal, God cannot change. Change involves going from one state to another. Change, therefore, necessarily involves time. But God is timeless. And for that matter, what would God change into? God is perfect. The only place you can go to from perfect is imperfect. As I mentioned above, if God were imperfect, he wouldn’t be God. God’s immutability is why he is always faithful: “The gifts and the call of God are irrevocable.” (Romans 11:29) God cannot contradict himself; God cannot change.
 Catechism of the Catholic Church 200. The Christian belief in a Trinitarian God – one God in three persons – does not contradict a belief in one God. The Trinity, however, will have to be the topic of a future posting.
 Fr. Robert Barron, Thomas Aquinas, Spiritual Master (New York, Crossroads Publishing Company, 2008) at 78.
 CCC 213.
 Barron at 61.