Trinity Sunday

Definition and Meaning

Trinity Sunday is the Sunday immediately following Pentecost. It is a day for remembering and confessing the doctrine of the Trinity, which holds that God is one while existing in three persons (distinct personal beings): the Father, the Son, and the Holy Spirit. Whereas other feasts commemorate events such as the Nativity or the Resurrection, Trinity Sunday is distinctive in that it commemorates a doctrine itself. Its date varies from year to year with the date of Easter, generally falling between mid-May and mid-June. The liturgical color used in the church year is white.

Biblical and Historical Background

The word "Trinity" does not appear in the Bible. As grounds for the doctrine, the church cites the baptismal command of Matthew 28:19 ("in the name of the Father, and of the Son, and of the Holy Ghost"), the benediction of 2 Corinthians 13:14 (13:13 in some versions), and the account of Jesus' baptism (Matthew 3:16–17), among other passages. The doctrine's formulation was developed through the Council of Nicaea (325) and the Council of Constantinople (381) and set forth in the Nicene Creed.

The practice of setting this day apart spread region by region in the medieval Western church. Pope John XXII is reported to have extended its observance to the entire Western church in the fourteenth century. In the Anglican and Lutheran traditions, the Sundays following this day have been counted as "the first (second, third, etc.) Sunday after Trinity." The Eastern Orthodox Church regards Pentecost itself as the feast of the Trinity and observes the following Sunday as the Sunday of All Saints. The hymn "Holy, Holy, Holy! Lord God Almighty" is said to have been written for Trinity Sunday by Reginald Heber, a bishop of the Church of England.

Practice in Korean Churches

The doctrine of the Trinity is confessed by nearly all Protestant denominations in Korea. The differences among denominations lie not in doctrine but in whether they observe this day as a distinct feast.

• Denominations that follow the church year: The Anglican Church of Korea and the Lutheran Church in Korea observe the day according to their service books. The Catholic Church also keeps the same day as the Solemnity of the Most Holy Trinity. In the Korean Methodist Church, the Presbyterian Church of Korea (Tonghap), and the Presbyterian Church in the Republic of Korea, congregations that use denominational worship resources or the Revised Common Lectionary (a table assigning Scripture readings for each Sunday according to the church year) preach on the theme of the Trinity and sing related hymns. Some churches also recite the Athanasian Creed together.
• Churches that place less emphasis on the church year: Many congregations in other Presbyterian denominations and in Baptist and Pentecostal churches do not mark the day separately. In these churches as well, the doctrine of the Trinity is regularly confessed through the Apostles' Creed, the benediction, and the baptismal formula.

Because Pentecost, the Wheat Harvest Thanksgiving (Maechu Gamsajeol), and the memorial Sundays of June follow one another closely at this time of year in Korean churches, Trinity Sunday is generally observed mainly by churches that follow the church year.