"It is not with God as it is with us. He does not look ahead to the future, look directly at the present, look back to the past. He sees in some other manner, utterly remote from anything we experience or could imagine. He does not see things by turning his attention from one thing to another. He sees all without any kind of change. Things which happen under the condition of time are in the future, not yet in being, or in the present, already existing, or in the past, no longer in being. But God comprehends all these in a stable and eternal present.... Nor is there any difference between his present, past and future knowledge."Why must God experience things in an eternal present? Allow me to play wannabe mathematician for a moment. Picture two events that took place two thousands years apart (say today and Jesus' fifth birthday). Now, remember that since God is eternal he experienced infinite periods of time both before Jesus' fifth birthday and after today. By comparison to the periods of time before and after that two thousand year span, the span itself reduces to a near infinitely short period. Now take a point in time 100 million years before the birth of Jesus. God's existence before and after that span of 100,002,000 years is also infinite. So how does the hundred million year period compare with the two thousand year period? Well, as a percentage of eternity, they're equal. The 100.2 million divided by infinity is the same as 2000 divided by infinity.
Bring into this God's unchanging nature, and you have the Eternal Now.
Maybe this is a function of my overly intellectual approach to the faith, but this idea has always have a peculiar hold on me. In God all things are brought together. The life, death and resurrection of Christ is not some ancient event. For God (and for us in the mass despite our temporal limitations as finite beings) his suffering death and resurrection are always now. At every given moment Christ is suffering for our sins, past and present, because for God each moment of our lives is simultaneous with the crucifixion.
In this sense, I've sometimes thought of the sacrifice of the mass as our own moment out of time. In celebrating the mass we experience the same moment, fixed in real human history yet eternal in God's experience, in union with billions of other souls throughout history. As we gather round the alter, we share that eternal moment of God's sacrifice with Karol Wojtyla celebrating his first mass, with St. Therese, with St. Francis, with St. Thomas Aquinas, with countless Catholics throughout history whether gathered in grand cathedrals, small chapels or a priest with his mass kit on the battle field or in the catacombs, with the apostles themselves at the Last Supper, and with Mary as she watched her son and Savior hang upon the cross. All of us, the Body of Christ, experience God's Eternal Now once each week. Sometimes even once each day.
It may be hard to remember when the kids are squirming. But that's why we're all there.