A colleague at work relayed a story to me from his school days that got me to thinking. My colleague, who isn't Catholic, attended a Catholic school as a boy. One day he asked a question in religion class concerning some seeming paradox of the Faith. Several students had given their own personal answers and several others had admitted they had never thought about it. What bothered my colleague, however, was the teacher's answer.
After hearing what the other kids in the class had to say, he said "Okay, you've heard some answers from some of the others. Or, you can always take the old Catholic cop-out and say it's a mystery."
What bothered my colleague about that answer was that he felt like the teacher was undermining the very Faith to which the school is supposedly dedicated in its founding mission. However, I got to thinking after he told me the story: How many Catholics out there really do think of the notion of "mystery" as a sort of cop-out, and even use it as such?
Most Catholics today, if asked to explain what a mystery is, would come up with something like "a mystery is something we can't understand, but we believe it anyway." But there's more to it than that.
A mystery is a truth that touches on or intersects with the nature or person of God Himself. And because of that, a mystery is infinite.
Think of a truth, like some kind of mathematical or physical reality, like a room that can be measured and characterized. Even a complex room can be fully mapped, and even if it's too much for one person to know on his own, the room can be fully known in a collection of minds or in (say) a computerized dataset.
Some would say, then, that a mystery is like a room which is known only through a set of read-outs because it is inaccessible to us directly--a room with locked doors and bars on the windows.
A mystery, however, is more like a cave that continues forever. it is a truth which, no matter how far we explore it and contemplate it and understand about it, there is always more. Not only more in depth, but more at every level. A room just has shape and dimension. But a cave has sand bars and rock floors, formations, rivers, broken pieces of rock, and possible treasures in ever nook and behind every stone. Each part of the cave can be explored not only as to shape and size, but as to history, composition, and geological significance.
This is what a mystery is like. As a truth, it is not only understood in terms of its meaning in a grammatical or rational sense. Because it touches on God's will, it has a moral dimension. Because it intersects with His person, it has a personal dimension. Because God's Will is salvific, a mystery has an historic dimension. Because the universe's makeup and construction are designed according to God's providence, it has a physical dimension. And because the human person is the divine image embedded into flesh, it has a biological dimension.
A mystery, then, is where anthropology, history, psychology, sociology, biology, physics, geology, astronomy, and cosmology all intersect with theology, which gives infinite dimension to each.