The Trinity is the foundation and framework for everything else that Christianity teaches regarding belief and practice. It is not in the first instance an abstract argument or philosophical puzzle, but an expression of who God is and how God lives. For the majority of Christians through the ages, God has been understood to be a living communion of Three-in-One. Christian identity is grounded in this divine reality. The vast majority of Christians worldwide have literally been baptized into the name of the Father, Son, and Holy Spirit as they entered the Christian community, the church. In worship the vast majority of Christians pray to the Father, Son, and Holy Spirit, or to the Father through the Son in the Holy Spirit.

The doctrine of the Trinity emerged as theologians of the ancient church sought to reflect upon the experience and expression of the divine Three-in-One in life and worship.Worship in particular has been important through the ages for articulating Christian identity, for it is the primary work that the Christian community as a whole undertakes to perform, the service that it offers to God. Christian worship not only gives expression to the trinitarian mystery. To a degree it reflects this mystery in its performance, and in the manner that it models many being together as one. At the heart of worship is a joyous celebration of the experience of communion. Through the centuries trinitarian theology has continuously been nourished, replenished, and articulated afresh through the ongoing experiences and expressions of this communion with God in ever new contexts. Communion is but another way to name the Trinity.