The way God reveals Himself in time and history is a revelation in some way of His eternal nature. As God created the world, He was not composing some sort of ultimate free verse. We look at the world, and unless we are suppressing the truth in unrighteousness, we see His eternal power and majesty. We see His Godhead revealed in the mountains, galaxies, fields, streams, plains, and oceans.
This being the case, how much more should we see His divine nature in the specific things He has given to us to teach us about His nature. In this category, we would of course include the Scriptures. In the Bible, God spells out for us, in big, block letters, what He is like.
But God also teaches us His nature in this aspect of worship. We have been communing with God from the beginning of the worship service to the present moment. But this is the culmination of that communion. We do not call this communion because it alone is communion with God. It is communion because it is the summit of our communion with Him.
When God communes with us, He is revealing to us what He is like. Before the world was created, God was communing with Himself. Before we were made, He enjoyed eternal fellowship and love. He did not create us in order to fill up a void or vacuum. His creation of the world was an instance of an eternally-sufficient God overflowing. And as He overflows, what overflows is His nature.
And this is why, when we sit down at this table, we are commanded to commune with one another. We are commanded to discern the body in one another. And why? Because this is what God is like.