The human person, by virtue of being created imago Dei, is an independent being, individually unique, rational, the subject of moral agency, a co-creator, and inherently social. Accordingly, human persons possess intrinsic value and dignity, implying certain rights and duties with respect to the recognition and protection of the dignity of themselves and other persons. These truths about the human person's dignity are known through divine revelation, but are also discernible through reason.
Officially, the competition is open to graduate students of any religious affiliation; but I imagine a secularist argument disagreeing with the prompt wouldn't be especially well-received, and I don't want to spend a whole day writing when I can be pretty confident of a negative reaction.
I agree with the second sentence, except for the word 'accordingly': humans possess intrinsic value and dignity, but, I would argue, not by virtue of our relationship with God. Rather, we possess intrinsic value and dignity simply by virtue of being rational agents. The third sentence is similarly flawed: reason provides the only objective grounds for respect for persons; while, by definition, revealed religion provides only subjectively sufficient grounds for any claim. Here I'm heavily influenced by Kant, especially his work in the Groundwork of the Metaphysics of Morals and Metaphysics of Morals.
Purely theological grounds for public policies would violate the principle of separation of church and state, a principle intended to protect both faith and the secular common grounds of civil society. So I would make the following three claims concerning a Kantian approach to practical philosophy: (1) the Categorical Imperative provides an objective foundation for civil and moral principles of respect; (2) this foundation is inherently secular, ie, does not depend upon any particular religious beliefs (and thereby offers the protections to the state of the church/state separation); and (3) is completely compatible with the idea of revelatory knowledge which might provide subjective foundations for additional moral (but not civil) duties (thereby also protecting faith).
I think a discussion of Kierkegaard's notion of a teleological suspension of the ethical would be appropriate here as well, though it's certainly not directly related to the Kantian line. As I read Kierkegaard, his analysis of Abraham leads to serious concerns about the ability of faith to provide any laws beyond devotion to God.