Sinful thoughts continually disturb a man. But if he does not cooperate with them, then he is not guilty of them. 

St. Ambrose of Optina

We must consider all evil things, even the passions which war against us, to be not our own, but of our enemy the devil. This is very important. You can only conquer a passion when you do not consider it as part of you.

St. Nikon of Optina

Run from places of sin as from the plague. For when fruit is not present, we have no frequent desire to eat it.

St. John Climacus

When struggles are replaced by consolations, and vice versa, they engender faith in God and indifference to the world.  Faith, having taken man by the hand, places him before God.

St. Ignatius Brianchaninov

The Christian is one who imitates Christ in thought, word, and deed, as far as is possible for human beings, believing rightly and blamelessly in the Holy Trinity. The lover of God is he who lives in communion with all that is natural and sinless, and as far as he is able neglects nothing good. The continent man is one who lives in the midst of temptations, snares, and turmoil, and who is eager to imitate with all his might those who are free from turmoil.

St. John Climacus

Virtue is nothing without the trial of temptation, for there is no conflict without an enemy, no victory without strife.

St. Leo the Great

The more we fear, the more we become susceptible to temptation. 

St. Paisios of Mount Athos 

Everyone needs the fire of temptations in order to be tried and instructed in patience. One must look at things with the point of view that Divine Providence is caring for our salvation: one person requires more, another requires less trials for patience and instruction, and for another, the time has not yet come.

St. Macarius of Optina