When the Arian heresy was spreading, the Fathers prepared an Office with canticles, responses, a Preface, and hymns, to be recited on Sundays.

[9] The Micrologies written during the pontificate of Gregory VII list no special Office for the Sunday after Pentecost, but add that in some places they recited the Office of the Holy Trinity composed by Bishop Stephen of Liège (903–920).

A new Office had been made by the Franciscan John Peckham, Canon of Lyons, later Archbishop of Canterbury (d.

[10] John XXII (1316–1334) ordered the feast for the entire Church on the first Sunday after Pentecost and established it as a Double of the Second Class.

[10] It was raised to the dignity of a primary of the first class, 24 July 1911, by Pope Pius X (Acta Ap.

Prior to the reforms of the Second Vatican Council, it marked the end of a three-week period during which church weddings were forbidden.

[11] In the traditional Divine Office, the Athanasian Creed (Quicumque vult) is said on this day at Prime.

A distinctive feature of Lutheran worship is the recitation of the Athanasian Creed on Trinity Sunday during Matins.

[15] In traditional Methodist usage, The Book of Worship for Church and Home (1965) provides the following Collects for Trinity Sunday:[16] Almighty and everlasting God, who hast given unto us thy servants grace, by the confession of a true faith, to acknowledge the glory of the eternal Trinity, and in the power of the divine majesty to worship the unity: We beseech thee to keep us steadfast in this faith and evermore defend us from all adversities who livest and reignest, one God, world without end.

[16]Almighty and everlasting God, who hast revealed thyself as Father, Son, and Holy Spirit, and dost ever live and reign in the perfect unity of love: Grant that we may always hold firmly and joyfully to this faith, and, living in praise of thy divine majesty, may finally be one in thee; who art three persons in one God, world without end.