Omnipotent means 'all powerful'. We express our belief in God being all powerful through the creed, "We believe in God the Father, Almighty."
Science has discovered that energy (and matter) cannot be created or destroyed. This is codified in the law of the conservation of energy. Since God created the universe out of nothing, he must be all powerful as his act of creating goes beyond the laws of nature. To create a particular object out of nothing would be to bring into existence a certain amount of matter or energy. But there is an infinite difference between nothing and something. ‘Nothing’ is hard to grasp as it is not just ‘empty space’ as empty space is itself a thing, defined using the laws of physics. Instead when we say nothing we mean the absence of any attribute or thing. Therefore, To create something from nothing, God must be infinitely powerful.
God is also logical. There are some things which are impossible to God. God cannot sin (more about this later). God cannot create absurdities. An absurdity is something illogical, eg a square circle. God's infinite power has the ability to create all possible things. Since there are infinitely many things that we could imagine that are not absurd, then God can create infinitely many things, so his power must therefore be infinite.
Omniscient means “All knowing” (1 Jn 3:20 see CCC 208). God has infinite, unlimited knowledge. As the creator who sustains creation at every instant God knows everything that takes place within the order he has established. God is also outside of time as time is a part of the physical world. This also means that God’s knowledge of all things is a single act, He cannot learn or forget, He simply knows. He knows every possibility. He knows what every person has done and what every person will do, or could do.
God knows what He has made you for and knows which path will lead to your greatest ultimate happiness. If you follow God’s will, this will be the path he leads you down, it may be hard, but it will be the best. This path is what we call your vocation, your calling.
Omnipresent means ‘all present’ or ‘present everywhere’ (CCC 2671). When we say God is present, we do not mean it in the ordinary sense of the word. As our transcendent and infinite creator He is not present like one human being to another. He is working constantly, sustaining all creation and through his knowledge and power every place and time is present to Him. He ‘sees’ every moment and can act on every moment, so he is present to each one. This type of existence outside of time is what we call eternal, or beyond time. This is not a time not even an infinite timeline, it is beyond time itself. To God your birth is just as present as your grandmother's birth, which is just as present to Him as the moment of creation. He is not distant from the world as he is keeping it in existence at every moment.
Since God must keep something in existence for it to exist every moment, time and place that exists He is present to. If He were not, then it would not exist. So He is present at every single moment of your life. Even the most mundane is present to Him and known by him as Jesus said, "even the hairs of your head are all counted." (Luke 12:7).
God's presence is always one of love. Love is according to St John Paul II a “sincere gift of self” and since God is giving himself eternally to sustain creation, He is present always in Love. He wills to give himself to us personally if only we would let Him.
God is infinite. Since we have briefly explained God’s omnipotence, omniscience and omnipresence we have a better idea of what this means. An infinite God must be perfect. If an imperfection is the lack of a good thing then in every attribute of God there can be no imperfection as what could be lacking from omnipotence? Omniscience? Or omnipresence? Every restriction we see is only possible because of the material world we exist in. But since God is transcendent everything that could allow for imperfection is gone, the possibility to be too big doesn’t apply as God isn’t material. The possibility to be ugly is gone as He is invisible. The possibility to be flawed is gone as He is beyond it all, This is what we call perfection in God. The fact that he is beyond every imperfection.
“God is mystery” (CCC 206). In theology we can speak of God in two ways, negatively and analogically.
Negatively we cannot say what God is only what He is not (Of course this doesn’t mean that God is negative). As the creator we cannot say that God is finite as His act of creation is beyond restriction, this means that He must be not-finite or what we can infinite. The consequence of this idea is that we can never actually know what God is, we can only look at creation and say that He is not like it. Or in other words God is mystery!
When we speak about God by analogy, we don’t mean it in the usual sense. What we mean is that God is kind of like X. For example when we say that a dog is good we mean ‘good’ in a different way to if we said that Europe is good. This means when we say that God is good it is meant in a different but not unrelated way. This also means that we cannot know God exactly, and therefore He is mysterious to us.
Just because God is mysterious doesn’t mean we cannot know something about him as both ways of speaking about God should show. I will never fully understand the universe, but I can know something about it, maybe even a lot about it. God is a bit like this, I will never comprehend Him, but I can know something about Him.