The relation between the Christian theologian and revelation is different from that between the Christian philosopher and the objectivity of his speculative content. While the theologian reflects about the contents of faith by the inner coherence of the Christian misteries and his fidelity to the sources of Revelation,
the Christian philosopher has the world as object of reflection, using the rational method to investigate those aspects of the Christian mystery compatible with reason. Christian philosophy theorically justifies itself like any other type of philosophy, since it mantains its formal specific character on the strenght of evidence and argumentation. If there is a difference from the others, it would probably be assuming revelation as a guide, for it allows the christian philosopher to enter a zone that invites him to think about something that, instrinsically, is beyond his own forces.
The distinction of orders is the key element that allows us to distinguish without separating, and uniting without misleading the use of reason from the theologian when rationally speaking about God, with the use of reason from the christian philosopher when speaking about the world. As St. Thomas states, there is a generic difference between theology and philosophy: Although theology and philosophical theodicy have God itself as material object, they have different formal objects, since theology reaches God regarding his deity while theodicy tries to reach God from the formal object of the reason of entity; while theology does it in the light of revelation, philosophy does it from natural reason.
The distinction between the philosophical and the theological field is such that it is impossible that a single subject can know and at the same time believe the same truth.
The distinction between orders is another aspect of the subordination of sciences, a key element to be able to understand that the limits between the different rational accesses to reality allow areas of mutual help and meeting.
They are not produced by discontinued leaps but create common areas in which the conclusions of a superior knowledge are the principles of an inferior knowledge. In catholic theology we distinguish three different orders of the divine knowledge: first, the one achieved by the vital experience of God, which is that of the mystics and the blessed ones; second, the one that we have of God himself as object of reflection of the revealed theology and, third, the knowledge of God as first cause of the being of things, which has a marked methaphisical formality.
These three orders are subordinated, so that the theological knowledge of God imperfectly participates of the perfect vision of God achieved by the saint; and the rational statements about God benefit from the light of the faith with which the theologist reflects. The motives are also different in this distinction of orders, for the motivation of the philosopher lies in the intrinsic truth of things, while the motivation of the theologist is the authority of the God that reveals.