The heart has become a battlefield between love and lust. The more lust dominates the heart, the less the heart experiences the nuptial meaning of the body. It becomes less sensitive to the gift of the person, which expresses that meaning in the mutual relations of man and woman. Certainly, that lust which Christ speaks of in Matthew 5:27-28 appears in many forms in the human heart. It is not always plain and obvious. Sometimes it is concealed, so that it passes itself off as love, although it changes its true profile and dims the limpidity of the gift in the mutual relationship of persons. Does this mean that it is our duty to distrust the human heart? No! It only means that we must keep it under control.
Pope John Paul II, Theology of the Body (General Audience, July 23, 1980)
In general, I would agree, though I choked a bit on the last few comments. To me, it seems obvious that we should distrust the human heart–Jeremiah 17:9. And your title brought to mind that pop song again :)
The Pat Benatar reference was wholly intentional. :-)
Bear in mind that the Pope had been teaching systematically on this subject for over a year at this point; there’s a lot that’s assumed in his use of words. I don’t think he would disagree that we should regard the heart (especially if you mean the way we can be led by our emotions to disregard reason) as always capable of deceit. In fact, that’s what he was just teaching, wasn’t it? But I think he was trying to caution us against taking an opposite extreme position of regarding real human relational responses–trust, awe, tenderness, concern, desire, joy–as “really” something else. Bear in mind that when he teaches he has to have in view not only certain conservative extremes (like regarding all human good as masked human evil) but also certain liberal extremes (like regarding all human good as expressions of economically dominant cultures oppressing the weak).
And, after all, even if I must guard against the deception by which lust masquerades as love (isn’t that the sort of thing Jeremiah has in mind?), I certainly cannot “love [my] wife as Christ loved the Church” if I do not believe Christ’s human heart, and mine, can be moved to just such love.