Helen Keller somewhere said, "It is wonderful how much time good people spend fighting the devil. If they would only expend the same amount of energy loving their fellow men, the devil would die in his own tracks of ennui."
Which might introduce the question: Is it best to "fight the devil" -- that is, oppose weaknesses in ourselves and others -- or cultivate and encourage the strengths in ourselves and others? Given one had to make the choice, that is.
Interesting question. I think honestly i would consider the cultivation of virtues to be the way forward, and that fixing our shortcomings goes along with it, like the other side of the same coin.
I think that certain cultures and outlooks develop among different sorts of people based on cultivating virtue or resisting weaknesses. Few people will be lucky enough to posess some genuine talent or ability, and the good in their life will be the cultivation of that best part of themselves. That is their virtue, and their virtuous life. Many people (most infact) will not have any particular talent, ability/virtue so to speak. As such their perspective and moral framework will be one of comparison to the other virtuous group, a re-sentiment. Their virtue will emerge from a focus on the not having, the restraint, and the denial of those things the able have, demonising it to legitimate themselves.
This group of people i think have been the target of religion, especially in the Judaeo-Christian tradition, and these 'sins' often dont actually amount to bad things, but represent resentiments and/or things that lead to a less pacified and servile people. (useful for an institution of religion to reinforce as sins).
As such i think that choosing to focus on 'resisting the devil' will often amount to exercising this resentiment based morality, and lead to a reinforcement of a stifled and repressed sort of existence. That this process of focusing on our evils, our sins is itself the sickness that needs to be broken out of.
Due to the profound effect in western culture that the Judeo-Christian tradition has had, I think it is something that effects even the non-religious, permeating the everyday interactions in society through class issues, politics and discriminations to how we talk about people and gossip to our nasty edged newspapers and celebrity obsessed culture. Theres this pervasive mind-set fixed in the not having the resentiment and defining that as the norm. I think this is a damaging and broken perspective that persists in our world.