Christ told His friends, that is, His disciples, to beware of the leaven of the Pharisees and scribes, meaning by leaven their false pretence. For hypocrisy is a thing hateful to God, and abominated by man, bringing no reward, and utterly useless for the salvation of the soul, or rather the cause of its perdition. Though sometimes it may escape detection for a little, yet before long it is sure to be laid bare and bring disgrace upon them, like ill-featured women, when they are stripped of that external embellishment which they had produced by artificial means. Hypocrisy, therefore, is a thing foreign to the character of the saints. That it is impossible for those things that are done and said by us to escape the eye of the Deity, He showed by saying: “There is nothing covered that shall not be revealed; neither hid that shall not be known.” For all our words and deeds shall be revealed at the day of judgment.
Our holy fathers have renounced all other spiritual work and concentrated wholly on this one doing, that is, on guarding the heart, convinced that, through this practice, they would easily attain every other virtue, whereas without it not a single virtue can be firmly established.
By the death of martyrs religion has been defended, faith increased, the Church strengthened; the dead have conquered, the persecutors have been overcome. And so we celebrate the death of those of whose lives we are ignorant. So, too, David rejoiced in prophecy at the departure of his own soul, saying: 'Precious in the sight of the Lord is the death of His saints.' He esteemed death better than life. The death itself of the martyrs is the prize of their life. And again, by the death of those at variance hatred is put an end to.
Men who are leading a spiritual life see by the eyes of their heart how the devil lays his snares, how the angels guide us, and how the Lord, in His Sovereign power, allows the temptations, and how he comforts.