The book briefly outlines Orthodox moral teaching: it examines the foundations of Christian morality - the commandments that were given to man by God first in the Old Testament (Decalogue, or Decalogue), and then in the Sermon on the Mount of the Lord Jesus Christ (the Beatitudes); explains the relationship between the Old Testament Law, the natural moral law and the Law of Christ; the concept of sin is analyzed - both in its essence and in specific manifestations; the foundations of Orthodox asceticism are considered - the teaching about ways to resist sin and achieve a spiritual state in agreement with the will of God for man, prayer. The book “Fundamentals of Orthodox Moral Teaching” together with two others - “Fundamentals of the canonical structure and liturgical life of the Orthodox Church” and “Fundamentals of Orthodox religious doctrine" - is intended for use as a teaching aid in the system of additional religious education, in the process of catechesis, as well as for educational activities in parishes and outside the church fence. The publishing layout is saved in PDF A4 format.