Manuscript Leaf with the Trinity in an Initial T, from an Antiphonary

Master of the Riccardiana Lactantius
Made in Florentine, Italy

Public domain scan of mensural notation, illuminated medieval manuscript, 13th-14th century, free to use, no copyright restrictions image - Picryl description

The concept of the Trinity is a central doctrine of Christianity that refers to the belief in one God who exists as three distinct persons: the Father, the Son (Jesus Christ), and the Holy Spirit. The three persons of the Trinity are equal in power and glory, and yet distinct in their roles and relationships with one another. The Father is the source of all that exists, the Son is the redeemer of humanity, and the Holy Spirit is the comforter and guide of the Church. The doctrine of the Trinity is rooted in the teachings of Jesus and the apostles, as well as in the early Christian Church's reflection on the nature of God and on the experience of God's presence in the world. The Trinity is a mystery that transcends human understanding and cannot be fully grasped by the human mind.