If a man purifies his heart and uproots from it all sin against the Lord; if he labors diligently to acquire Divine knowledge and succeeds in seeing with his mind that which is invisible to many, he must not through this exalt himself over others. Who among creatures is purer than an incorporeal being and who has more knowledge than an Angel? Yet, having exalted himself he was cast down from heaven like lightning. His pride was regarded by God as impurity.
Do we forgive our neighbors their trespasses? God also forgives us in His mercy. Do we refuse to forgive? God, too, will refuse to forgive us. As we treat our neighbors, so also does God treat us. The forgiveness, then, of your sins or unforgiveness, and hence also your salvation or destruction, depend on you yourself, man. For without forgiveness of sins there is no salvation. You can see for yourself how terrible it is.
The adversary of our life, the devil, employs many devices to make our sins seem small to us. Often he cloaks them with forgetfulness, so that, after suffering a little on their account, we no longer trouble to lament over them. But, my brethren, let us not forget our offences, even if we wrongly think that they have been forgiven through repentance; let us always remember our sinful acts and never cease to mourn over them, so that we may acquire humility as our constant companion, and thus escape the snares of self-esteem and pride.