I always found it hard to figure out how exactly the Holy Trinity worked, and how one God, could be in 3 different persons. But after reading in the word and meditating about it, I found out a simple way to explain it to myself.
Have you ever talked to yourself? Argued with yourself? Lied to yourself? Was disappointed in yourself? It might seem that we have more than one person with in us, but we know that we are individually one person.
This may not be the absolute correct way to explain it, but in a way it kind of works in my head. God has manifested himself into a human flesh when he came down. So He was 100% human, and at the same time He was 100% God, but He limited him self to time, temptation, hunger, pain, etc.
With this example, when Jesus said, “My Father, if it be possible, let this cup pass from me; nevertheless, not as I will, but as you will.” (Matthew 26:39), it’s not that he was talking to the Father God, as another god, but in a way he was talking to the Father which is himself. At first, it may seem strange or even hard to explain, but again going back to the simple explanation I made for myself, it might not be as complicated. Many times I know I need to do something and I should, but then again, I argue with myself and tell myself I don’t want to do it, but I know I need to. So in the same way, I believe that God is one, but has 3 different manifestations, that are characteristically different.