I happened to notice a little book on a shelf this morning I'd picked up a couple of years ago called On Union with God, by (it is said) St. Albert the Great. (A different translation of this brief work is available on-line.) Since I'm in the process of trying to understand what union with God means for a lay secular person, I thought now might be a good time to read it.
It is, of course, written from the perspective of, and for those in, the religious life. My working hypothesis is that we can't simply take this perspective and, by shoehorning, shrinking, or whittling, make it fit the secular (and in particular the married) life.
So what can we draw from the one perspective to apply to the other? I'm still trying to figure that out. Generally speaking, though, I think there are some things that apply to all Christians equally; some that apply to all Christians, but in different ways according to their different states in life; and some that apply only to a particular state. Works like On Union with God can only be interpreted for married people in light of what applies particularly to the married state, and what applies particularly to the married state hasn't been the subject of the reflection and study that what applies particularly to the religious state has been.
But once you agree that perfection in this life consists in "the intellect [being] perfectly illuminated, according to its capacity, with the knowledge of God, who is perfect truth, ... the will [being] perfectly focused on the love of the perfect good, and ... the memory [being] fully absorbed in turning to and enjoying eternal happiness, and in gladly and contentedly resting in it," you can see why the religious state is a higher calling than the secular state without feeling somehow denigrated if you're not a religious.