The abbot Pastor speaks of a way in which we may overcome evil thoughts.
The abbot Isaiah once asked the abbot Pastor about evil thoughts which troubled him. Pastor answered him, "Just as clothes which are put away for a long time in some trunk, and not taken out at all, moulder and decay, so the evil thoughts of our hearts, if we do not put them into action, after a long time will fade away."
Reference: http://www.archive.org/details/wisdomofdesert00birmrich