In the Western Church, it was decreed in 1334 that the Sunday after Pentecost would be marked as the Feast of the Holy Trinity, or Trinity Sunday. This feast sums up the teaching of the Church on the Trinity of God. Holy Trinity Day is also the day of the Creed.
The Biblical readings of the day speak of God’s mystical being, which they say surpasses human understanding. God is one, but he has announced himself to mankind as the Father, the Son and the Holy Spirit. He appears as Creator, Redeemer and Sanctifier. Faith does not work on the being of God by making factual distinctions, but in wonder, praise and celebration of his acts of grace.
In the Western Church, Trinity Sunday marks the beginning of the half of the church year which has fewer feasts. The Feast of the Holy Trinity is one of the 24 most important feasts of the Catholic Church.
