Setting medieval visions of monks beating themselves with horsewhips aside for a moment, mortification, in a spiritual sense, simply involves a process through which one puts some aspect of one’s sinful nature to death. In my view, this does not mean actively punishing and torturing ourselves, but rather actively choosing what is right over actively choosing what we know to be wrong despite the pleasure and comfort the wrong choice apparently offers. The conscious denial of the apparent pleasure and comfort inherent in the wrong choice initially causes suffering, which is exactly what must be overcome or put to death for spiritual growth to occur.
But mortification alone – the killing of vice and immorality – forms only half of the equation. It is not enough to simply mortify – one must also vivify. In other words, when we succeed in putting something negative within us to death, we must also strive to bring something positive to life. The subjugation of a vice must also bring forth virtue. The vanquishing of immorality must instill morality. The dissolution of a false self must serve to invigorate the real self. Simply put, mortification is a "no pain, no gain" paradigm. The pain and suffering we experience by denying an apparent pleasure or comfort in sin is superseded by the pleasure and comfort of the spiritual gain we obtain through discipline. Seen in this way, mortification and vivification are a dyad; together they form a crucial component for spiritual development.
Unfortunately, this dyad has been completely inverted in our modern world. Though the essential pattern of mortification and vivification still exists, their poles have been transposed. Our modern world demands we mortify the spirit (by this I mean virtue, morality, the divine spark, the real self) and vivify the flesh (by this I mean vice, immorality, the demonic, false selves). The former is accomplished primarily through atheism and denial of the metaphysical while the latter is promoted through the media and modern bureaucracy. Inverted mortification and vivification rejects the reality of sin, promotes the avoidance of suffering caused by self-denial, and lures people into sin through the following lie: all gain; no pain.
This inverted mortification seeks to put the positive to death and strives to bring the negative to life. The subjugation of virtue must be replaced by vice. Morality is vanquished in order to liberate immorality. False selves are enlivened and animated while the real self is deadened. Of course, the core of the inversion is making people believe that the positive they are mortifying is actually a negative while the negative they are vivifying is actually a positive. Thus, inverted mortification and vivification are a demonic dyad; together they form the perfect weapon against spiritual development.
True mortification involves voluntary self-denial and delayed gratification. One sacrifices the apparent comforts and pleasures inherent in sin in the short term to attain virtue and spiritual development in the long term. Inverted mortification, on the other hand, emboldens self-indulgence and instant gratification. One denies and betrays the spirit in the long term to achieve material comforts and pleasures through sin in the short term.
The acceptance of this inverted mortification and vivification invites self-damnation of the soul, which is exactly why the inversion was created and also why it is currently being so vigorously deployed.