The book contains a series of lessons where, through the text of the Divine Liturgy of Saint John Chrysostom, the conditions of faith and the ways in which the faithful are led to the knowledge of God are presented. At the same time, the content of the supernatural act of the Eucharist and Communion is exposed and developed, which, as an act of a people gathered together in the name of Christ, define the being and what they have of the faithful and lead them to familiarity with the actions of the Holy Spirit and through him in union with Christ.
The main element of the lessons is to remind and clarify the terms of the faith. That is, in essence, to comment on and interpret the "what" of the Church - what the Church is. But also to describe the "how" of the Church - how the Church moves through history. So they have a catechism character, or, in simpler words, it is a catechism for adults.