Man, as a created being, was separated from the uncreated God by two barriers: natural difference, and after the Fall also by sin. The Son of God, the Lord Jesus Christ, by His Incarnation and the union of divinity and humanity in Himself, removed the first barrier, and the second by His death on the cross. On the day of Pentecost, He sent us the grace of the Holy Spirit to effectively help us in cleansing ourselves from sins. But God does not save us without ourselves, for sin still continues to live in us, and therefore alienates us from God and requires our own efforts to combat it to eradicate it. To do this, we need, first of all, an awareness of sin as such and its disastrous severity, a vision of our sins, as well as ways to combat them and defeat them with the help of God. This is what this book is about, containing pearls of experienced patristic wisdom so that everyone can successfully walk this difficult path.