V. The Sacramental Sacrifice Thanksgiving, Memorial, Presence

From The Catechism of the Catholic Church

1375
It is by the conversion of the bread and wine into Christ’s body and blood that
Christ becomes present in this sacrament. the Church Fathers strongly affirmed
the faith of the Church in the efficacy of the Word of Christ and of the action
of the Holy Spirit to bring about this conversion. Thus St. John Chrysostom
declares:

PART TWO: THE CELEBRATION OF THE CHRISTIAN MYSTERY

SECTION TWO THE SEVEN SACRAMENTS OF THE CHURCH
- CHAPTER ONE THE SACRAMENTS OF CHRISTIAN INITIATION
  - Article 3 THE SACRAMENT OF THE EUCHARIST
    - V. The Sacramental Sacrifice Thanksgiving, Memorial, Presence

From The Catechism of the Catholic Church – rosary.team