Blessed are the pure in heart, for they shall see God. Everything we do, our every objective, must be undertaken for the sake of this purity of heart. This is why we take on loneliness, fasting, vigils, work, nakedness. For this we must practice the reading of the Scripture, together with all the other virtuous activities, and we do so to trap and to hold our hearts free of the harm of every dangerous passion and in order to rise step by step to the high point of love.
How can one say that a man has attained purity? - When he sees all men as being good, and when none appears to him to be unclean and defiled - then he is indeed pure in heart.
Those who attend the divine service of the Orthodox Church must bear in mind that its purpose is to prepare us for the joyful service of God in heaven; that in serving God with the body, it is still more necessary to serve God with the soul and a pure heart; that in hearing divine service they must learn to serve God as those saints served him, whose lives, and works of faith, hope and love, we hear of during the service; that God should, above all, be served in deed and truth, and not only by words and the tongue.
It is not always possible to fulfill the usual rules; one must take circumstances into account and try to fulfill what they make possible, as far as one can. The demons themselves are not unmindful of this law. So, being in constant enmity with us, they prevent us from doing what is possible and urge us to do what is impossible.
A righteous person who is wise resembles God: he never disciplines anyone in order to take vengeance upon a wrongdoing, but only so that the person may be set aright, or that others may be deterred.