Bear with me as I tease out an analogy. Like all analogies, it will break down, but I'm curious to see what the correspondences offer.
Imagine sin as a wound upon the soul. Like physical wounds, sin causes pain, but certain kinds of attention to the wound also produce a temporary relief. To heal a wound causes pain, but generally increases discomfort rather than offering immediate relief. Indeed, sometimes healing the wound requires removal of a portion of the body, and in the case of the soul, the operation is more like curing cancer than, say, a laceration, since 1) the soul is simple and indivisible, and 2) is therefore effected entirely by the sin, rather than in a "part."
Imagine humans as animals. Like animals, humans have instinctual patterns governed by an innate nature. If an object comes flying by a man's eye, he will blink. If a woman trips and nearly stumbles over a precipice, her heartbeat increases and adrenaline pumps through her body, preparing it for the perceived injury that is possible. When cornered, an animal will make a show of size, sound, and fierceness in order to intimidate a perceived predator into flight. Barring that, the animal will fight with abandon, until either the predator is neutralized, or the opportunity for flight presents itself.
The physical realities of wounds and animal instincts are useful analogies for the spiritual situation that humans face with one another. When a man is in sin, there is a kind of pleasure he gets from indulging the sin, even though he may (depending upon how self-deceived) regret the indulgence later. When the sin is exposed to the Balm of Christ offered in the Gospel, there is a real chance that the response will be more like the cornered animal than a lovesick orphan. This can happen in different ways, though. For the creature who cannot imagine healing, or has grown to love the wound and believe it to be natural to her soul, the instinct of ferocity at being cornered is truly a response to perceive predation--they sense the immanence of death (i.e., my way of being must be no more), and the response is threatening, shouting, violence, even murderous violence.
For the creature who is merely shocked at the pain of the Gospel, the bowing up may be more like an involuntary response to pain than an instinctual response to predation. Once past the initial shock, the posturing resides into something more normal, perhaps even curious as to what this new intrusion into her environment means.
The effects of applying Christ to the problem of sin is not limited to unbelievers, either. Christians can respond to Christ in the flesh or in the spirit, and often times there is a measure of confusion whilst the two opposing natures fight for mastery of the soul's affections, beliefs, and overwhelming desire. The difference is that the Christian always has the Spirit united with her soul in such a way as to give opportunity for a willing reception of Christ's balm applied to the sin. For the unbeliever, there is no guarantee that the Spirit will be working in that one's or another's soul for reception, or, that the work will be one of union (i.e. the Spirit exerts influence over the soul, but not through uniting with it, at least not in a vital way).
What's the use of such an analogy? For one it appears to engender pity, insofar as one is already able to pity wounded animals whose response to one's aid may be hostile, or even fatal. Another is that it affords a measure of patience and circumspection for the believer, who, though he or she is a new creation, still carries around habits and instincts of the flesh. A romantic mind tends to identify the spontaneous, immediate, and intutitive response with authenticity, truth, or even the work of the Spirit; but such things can as easily be the instincts of a wounded (fatally, but still in its death throes) flesh. It can be mastered, but not if one doesn't recognize its presence in the reaction to the balm of Christ.