My children, whatever grievous thing the devil, the enemy of our souls, reminds you of, make an effort to drive it away immediately without delay, for every delay brings about unfavorable consequences. The devil is completely vanquished with prayer and vigilance. The essence of watchfulness consists of being sleeplessly vigilant with the nous, pitting it against the passionate thoughts and fantasies of the vile demons. On this depends life or death, degradation or improvement. In other words, a soul that prays noetically and loathes and scorns the various evil thoughts is purified and sanctified with time.
Elder Ephraim of Arizona