The unclean spirit has a strong influence ( St. Seraphim of Sarov )
The unclean spirit has a strong influence only on the passionate; but those purified of passions he touches only indirectly and externally. A person in his youth cannot avoid being disturbed by physical thoughts. But he must pray to the Lord God, that the spark of depraved passions dies out at the very beginning. Then the flame within him will not become more intense.