The pastor at my church frequently articulates the central purpose of man in the following way: “We are angled mirrors, made to reflect the glory of God to his creation, and to reflect back the praises of creation to God.” So we are priests in the sense that we represent God to earth, and in the sense that we represent earth to God.
I take issue with the second part of this, not that we reflect the glory of God to his creation (which I believe we certainly do, as the only animals who bear his image), but the part where we “reflect back the praises of creation to God.”
For one thing, I am not sure that it is true. Creation does not need us to praise God. It does a better job than us! Deer and rivers do not need us to verbalize the praise they owe to God. Are they not praising him now, on their own? Can we not hear them, when we listen? And if we can hear them, how much more can God their maker hear them, who is attentive to the smallest creature he has made, and sensitive to the glory of everything he holds in existence by the continual lending of his own essence! If we were silent, would not even the rocks cry out?
But my more important objection is that this expression of our primary purpose frames it such that we are the agents, and God the patient. We are made so that we would do X to God. (reflect the praises of creation). This is the same as my objection to the Westminster Catechism’s answer to that same question of the purpose of man: “To glorify God and enjoy him forever.” In it too, we are made to do something to or for God, namely, to “glorify him.”
The verb “enjoy” escapes my criticism for the same reason the whole of the Catholic catechism’s answer does: the semantics of the word keep man as a patient. The Catholic answer is:
Of all visible creatures only man is “able to know and love his creator.” He is “the only creature on earth that God has willed for its own sake,” and he alone is called to share, by knowledge and love, in God’s own life. It was for this end that he was created.”
To “share in God’s own life” is an infinitely more satisfying answer to the question of our purpose. After all, what good reason can any parent give for “why they had their child” except that they wanted their child to share in their love? How much more true of our Heavenly Father!
In discussing this with a friend after church, we came to the conclusion that our priesthood is only one-way, not two-way. We are priests of God toward creation, not priests of creation toward God. What about how priests represent the people before God when they offer the Paschal sacrifices? Perhaps the difference is that, in that, we are not offering anything created, but the uncreated Christ back to God; and thus, our sacrifice and our worship have come from him. That still keeps us as patients.
So the angled mirrors analogy breaks down. Mirrors are two-way reflectors, transparent and imageless; they merely reflect the image of something else to the viewer. But we are ourselves images with substance, imago dei, less like mirrors, and more like tangible paintings or icons. In his great love, he has deemed that we would show forth his glory by our likeness to him, as we follow him into the great journey of theosis, of entering into his divine life.
It’s true that this works out so that we do glorify God, and so that we do order creation in ways that please God (as I am pleased by my children’s works of art). But somehow, this is not our purpose, but the results of it, radiating out from the great love of God which remains relentlessly fixed on us, like a star-crossed lover, without any ulterior motive.