A Muslim may ask:
If we think of the finite body of Jesus as a cup and the infinite God as the sea. Could you tell me how the sea could fill the cup?
First there is a problem with this illustration. The sea is physical element and the cup is also physical element. While God is a spirit and the body of Jesus is a physical element.
Let me illustrate to you how “the infinite fills the finite” by using a TV set (physical element) and the TV broadcast waves (non-physical element).
We all know that the TV broadcast waves (i.e. satellite or just analog antenna waves) is almost everywhere in our geographical location. When we adjust the TV to receive the channels broadcasted on these waves, something interesting will happen, we see a picture and hear an audio.
In a way, we could say that the infinite (waves) filled the finite (TV set). I hope that helped.