There
are said to be five reasons why God allows us to be assailed by demons.
The first is so that, by attacking and counterattacking, we should
learn to discriminate between virtue and vice. The second is so that,
having acquired virtue through conflict and toil, we should keep it
secure and immutable.
The
third is so that, when making progress in virtue, we should not become
haughty but learn humility. The fourth is so that, having gained some
experience of evil, we should ‘hate it with perfect hatred’ (cf. Ps.
139:22). The fifth and most important is so that, having achieved
dispassion, we should forget neither our own weakness nor the power of
Him who has helped us.
"Four Hundred Texts on Love". Second Century. From Philokalia, Vol. 2.
St. Maximos the Confessor
St. Maximos the Confessor