Theology is "the systematic and rational study of concepts of God and its influences and of the nature of religious truths, or the learned profession acquired by completing specialized training in religious studies, usually at a university or school of divinity or seminary." ( Wordnetweb.princeton.edu, SN: Theology) The key words here are 'rational' and 'learned'. It is a study of the mind. While this is all well and good (and I mean that...it is good and fruitful), it has a fundamental flaw, which is in dealing with the primary source - God.
Encounters with the Divine, which are the core of faith, are essentially experiential and a-rational. It is not that they (and their fruits, Faith) are unfounded or lack reason, but rather they are entirely beyond the capacity for systematic, logical examination. At base, they are matters of the heart, not of the mind. This shortcoming is not a new phenomenon or startling revelation. It is what the Angelic Doctor was referring to when he wrote "To one who has faith, no explanation is necessary. To one without faith, no explanation is possible."
A systematic, rational and learned approach to an inquiry of study has great value, to be sure, but to describe love as a set of biochemical receptor changes or compassion in statistical trend analysis misses the entire point. Such things defy reason, analysis or explanation. As Balzac said more succinctly, "We love because we love."