"When we pray to the Lord and say: 'Lead us not into temptation', we are not saying this so that we shall not be tried; that would be impossible. We are praying not to be overcome by temptation to the extent of doing something displeasing to God. That is what it means to not enter temptation. The holy martyrs were tried by their torments but, as they were not overcome by them, they did not enter into temptation, any more than someone who fights with a beast and is not devoured by it. When he is devoured, then he has entered into temptation. So it is with every passion, so long as one is not overcome by that passion."
From The Spiritual Meadow by St. John Moschos (No. 209).