It is also called Trinity Sunday, Christian feast in honor of the Trinity, celebrated in Western liturgical churches. The Sunday following Pentecost (the 50th day after Easter It is known that the feast was celebrated on this day from as early as the 10th century. Celebration of the feast gradually spread in the churches of northern Europe, and in 1334 Pope John XXII approved it for the entire church.
The doctrine of the Trinity means that there is one God who eternally exists as three distinct Persons — the Father, Son, and Holy Spirit. Simply stated, God is one in essence and three in person. When we break this definition down, we get three crucial truths: (1) the Father, Son, and Holy Spirit are distinct Persons, (2) each Person is fully God, (3) there is only one God.
Although our understanding of the Trinity is limited as Isaiah 55:8 says “For my thoughts are not your thoughts, neither are your ways my ways, declares the LORD.” The Trinity is another reason to worship GOD. He is bigger and more powerful and more beautiful than we can ever imagine or comprehend yet He has revealed himself to us in ways that allows us to have a real and genuine relationship with Him. The Trinity should cause us to desire to know Him more. It also allows us to trust Him fully because He is the source of eternal life and He is capable of accomplishing everything necessary for our salvation.
The reflections on the Holy Trinity should be an empowerment for us to act in love with our fellow Christians. The great love shared by the three Persons of the Holy Trinity lies at the fulcrum of salvation history. This love should guide us and mark us as Christians. Otherwise, the doctrine about the Holy Trinity would remain far-removed from our daily living. At our baptism, “In the name of the Father, the Son, and the Holy Spirit we have already been clothed with a God-like dignity which opens the door for the adventure of love we are called to share with the Divine. The Trinity is about our lives and how our life has been redeemed from the bondages of sin through a divine love. Unless we learn to breathe this love through our constant relationship with God himself, the doctrine of the Trinity remains a fossilized mystery which can never be related to our lives.