We need repentance. You see, repentance is not only going to a priest and confessing. We must free ourselves from the obsession of thoughts. We fall many times during our life, and it is absolutely necessary to reveal everything [in Confession] to a priest who is a witness to our repentance. Repentance is the renewal of life. This means we must free ourselves from all our negative traits and turn toward absolute good. No sin is unforgivable except the sin of unrepentance.
One should preach not from one's rational mind but rather from the heart. Only that which is from the heart can touch another heart. One must never attack or oppose anyone. If he who preaches must tell people to keep away from a certain kind of evil, he must do so meekly and humbly, with fear of God.