Making the devil die of ennui

How does one defeat the Accuser of the Brethren?

Came across this Helen Keller quote:

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. 

Some might think that the efficacy of the perfect law of liberty against the devil is unscriptural, as stated in such unscriptural terms, but I think it is worthwhile to consider these following statements by "those who seemed to be pillars":

But one whom you forgive anything, I forgive also; for indeed what I have forgiven, if I have forgiven anything, I did it for your sakes in the presence of Christ, so that no advantage would be taken of us by Satan, for we are not ignorant of his schemes.

Paul seems to be saying here that the Accuser's plans are foiled by forgiveness.  He seems to imply the same thing in his letter to the Ephesians, when he says, “Be angry, and do not sin: do not let the sun go down on your wrath, nor give place to the devil.”   Letting anger ferment into bitterness gives place to the devil. It is in fact one of the chief "wiles of the devil."

The apostle Kepha (Peter) says here:

Yes, all of you be submissive to one another, and be clothed with humility, for “God resists the proud, But gives grace to the humble.” Therefore humble yourselves under the mighty hand of God, that He may exalt you in due time, casting all your care upon Him, for He cares for you.  Be sober, be vigilant; because your adversary the devil walks about like a roaring lion, seeking whom he may devour.

It would seem that being caught up in the cares of self-promotion make you vulnerable to the devourer.  James makes a similar point in his epistle, quoting the same scripture as Peter from the Tanakh, that resisting covetousness and competitiveness (through submission to God) is resistance to the devices of the Accuser.  Taken in context, I think that the First Epistle of John also may suggest that loving one's neighbor and opening one's "bowels of compassion" to him is resistance to the antichrist spirit.  

It could be that there is nothing like "fulfilling the law of Christ" that would stop the Accuser and make him to die of ennui.