Trinity Sunday (Orthodoxy)

Sermon Recap: This Trinity Sunday sermon argues that mystery is not a problem to solve but a gift that draws us deeper into God. Using examples from quantum physics, it shows how greater knowledge often leads to greater wonder rather than certainty. The doctrine of the Trinity reminds us that God always exceeds our understanding. Drawing on Bell Tindall Riley’s idea of “unknowing,” the sermon describes faith not as mastering God but as trusting the One we cannot fully comprehend. Mystery is not the absence of God; it is often where God is closest. The Triune God may never fully make sense to us, but God makes sense of us.

Read/listen to the original sermon here.

(Given 5-31-26, St. Augustine's Church, Kingston, RI)

Artwork by Caleb Smith

In what might seem like a total contradiction to the spirit of the sermon, it's important to speak to what the Church has determined to be within the scope of its teaching about God. Orthodoxy (from Greek ortho = correct, + doxía = belief) in general is simply meant to describe doctrines (teachings) that the broader, historic Church has held to be biblically sound and generally agreed upon regarding foundational Christian theology. And no theological topic is better poised to show the importance of orthodoxy than that of the the Trinity.

For nearly four centuries the early Church argued extensively about how to make sense of the triune God (4th-8th centuries...and beyond in, some cases). Most of these arguments specifically focused on the nature of Christ (christology), but — because they were ultimately concerned with the relationship of Christ to the Father and/or the Spirit — I tend to consider them to be trinitarian at their core.

When a belief falls outside of the bounds of orthodoxy, it's technically referred to as heterodoxy (from Greek héteros = other, another, different, + dóxa = belief). However, when a a belief was particularly contrary (and potentially harmful) to orthodoxy, the bishops of the early Church would gather to discuss them and —more often than not — condemn such beliefs as heresy (from Greek haíresis = choice). The following are some (but not all) of the notable trinitarian heresies that were condemned within the first millennium of the Church:

• Arianism taught that Jesus was created by God and was not fully divine. Arians believed the Son was the highest creature, but not equal to the Father. The church rejected this because Scripture presents Jesus as fully God.

• Modalism (or Sabellianism) claimed that Father, Son, and Spirit are not distinct persons but simply different "modes" or roles that God plays. According to this view, God sometimes acts as Father, sometimes as Son, and sometimes as Spirit. The church rejected this because the Bible shows all three interacting with one another.

• Tritheism went in the opposite direction, treating Father, Son, and Spirit as three separate gods rather than one God. This undermines Christianity's belief in one God.

• Partialism suggested that each person of the Trinity is only one-third of God, like pieces of a pie. Orthodox Christianity teaches instead that each person is fully God, not a fraction of God.

While the councils of the early Church may not have ever "figured out" the Trinity for us, they did critical work in establishing the theological boundaries of orthodoxy so that we might exist in the space of unknowing more faithfully. As the sermon says, sometimes it's easier to start with what God isn't rather than make the mistake of believing that we've figured God out. Orthodoxy is a helpful tool that guards us from stepping into that same temptation as many — with all good intentions – have done over the long history of our faith.