My mom and I often have conversations where we puzzle over the awesome mysteries of life and the afterlife. It is something that occurs naturally after the death of a loved one. One topic we try to wrap our minds around is that of eternity. Living, as we do, in time and space, the concept of eternity is a strange one indeed. For to live in eternity is to live outside of time and space.
We Catholics can’t claim to understand much more about eternity than other human beings on this side of Heaven. But even in this life, we are granted certain small glimpses and foreshadows. Most notably, every time we attend the Mass, we gain entry into eternity. This is because the Mass is the earthly participation in the very worship of Heaven. The senses may not perceive anything; the church (or wherever the Mass is taking place) remains a physical place, and the people within it still move through time and space. But it is an article of faith that when we are at Mass, we are in communion with all souls who worship God: those in Heaven, those on Earth, and those in Purgatory. The only absence is that of those who are in Hell.
It is very difficult for my non-Catholic relatives and friends to understand this, but nowhere and at no time am I closer to my dad and my other deceased loved ones than when I am at Mass. They are right there with me. I know this to be true.
Catholics also see eternity in certain days–most especially Sundays and Fridays. In each and every Sunday, there is a glimmer of Easter. In each and every Friday, there is a shadow of Good Friday. This is why we owe our worship to God each and every Sunday, and why Sunday is traditionally a day of joyful feasting. This is why we are obliged to perform acts of penitence each and every Friday–be it the traditional abstinence from eating meat, or some other act. It is not so much that we remember Easter on Sundays and Good Friday on Fridays, as that we actually enter in to them and live in them to some degree.
I’m probably not explaining this too well. And ultimately, it may be understandable only to Catholics who understand and practice the faith devoutly. (Not that this is something particular to Catholics; I imagine it is understandable also to our Orthodox and Jewish brethren; indeed I believe this idea of entering profoundly and truly into past events originated with the Jews, in their annual commemoration of the Passover, for instance.)
In any case, eternity is an interesting thing to ponder, and our limited brushes with eternity are something for which to be grateful.