The Catholic Church has believed in the Real Presence of Christ in the Eucharist since its very beginning. This belief is rooted in the words of Jesus Christ himself at the Last Supper, as recorded in the Gospels and the writings of St. Paul.
Here's a breakdown:
* Scriptural Basis: The Gospels of Matthew, Mark, and Luke, as well as 1 Corinthians, describe Jesus taking bread and wine, saying, "This is my body," and "This is my blood." Catholics interpret these words literally, understanding that the bread and wine become the body and blood of Christ, though they retain the appearance of bread and wine.
* Early Church Fathers: From the earliest days of Christianity, the Church Fathers (theologians and leaders of the early Church) consistently affirmed the Real Presence. Figures like Ignatius of Antioch (early 2nd century), Justin Martyr (mid-2nd century), and Irenaeus (late 2nd century) wrote explicitly about the Eucharist as being more than just a symbol, but the actual body and blood of Christ. For example, Ignatius of Antioch, in his letter to the Smyrnaeans (c. 110 AD), referred to the Eucharist as "the medicine of immortality, and the antidote that we should not die, but live for ever in Jesus Christ." Justin Martyr, in his First Apology (c. 155 AD), described the Eucharist as "the flesh and blood of that Jesus who was made flesh."
* Consistent Teaching Throughout History: The belief in the Real Presence has been a consistent and continuous teaching of the Catholic Church throughout its history. It has been reaffirmed in numerous Church councils and documents.
In summary, the Catholic Church's belief in the Real Presence dates back to the institution of the Eucharist by Jesus Christ at the Last Supper and has been consistently taught and upheld since the earliest days of the Church.