It is a moment in which we step out of linear time into eternity so that we can be with him as he makes himself gift to us one time and for all. This is of course mystery. Our minds may have difficulty grasping the reality that we become present in eternity to Jesus Christ on the altar as he makes himself present to us in a sacrificial meal. Perhaps that is why we still have among us those who retreat to Jesus in the tabernacle rather than rally opening themselves to the mystery of the altar. It is difficult for the mind to grasp.
Mystery lies as well in the bread and the wine.
Yet it remains, as well, bread and wine. This is very difficult for the mind to grasp. Even the Church, which understood this to be so from the very beginning struggled with finding words to explain what it knew to be true. It was more than a thousand years, and then thanks to the pagan Greek philosopher, Aristotle, before we arrived even at a word to point to the mystery. For more than a thousand years faith persevered without words.