“When we cry, ‘Abba! Father!’ it is that very Spirit bearing witness with our spirit that we are children of God, and if children, then heirs, heirs of God and joint heirs with Christ—if, in fact, we suffer with him so that we may also be glorified with him.” (Romans 8:15b-17, NRSV)
In the 1826 hymn, "Holy, Holy, Holy," Reginald Heber celebrated the doctrine of the trinity with the words, "God in three persons, blessed trinity." This beautiful hymn reinforces the triune nature of God with such beauty and majesty, yet it offers very little help in understanding one of the thorniest doctrines of our faith. Controversies over the doctrine of the Trinity have plagued the church since its earliest days. Heresies emerged that carry names like Arianism, Docetism, Monergism, Modalism, Tritheism, and Adoptionism that characterize what the Trinity is not, a task much easier than defining what it is.
We search for analogies that help us understand the Trinity. Some argue that water is a helpful way to think of the Trinity since water can exist in liquid, gas, and solid forms. The problem with that analogy is that while it's three forms of the same substance, the environment determines its state. It's also a form of the heresy of modalism where only one mode can exist at any point in time. Others use the imagery of the sun, which includes the sun itself, its light, and its heat. This analogy lends itself to Arianism, a heresy that says God the Father created the Son and the Holy Spirit. There is no analogy sufficient to describe the Trinity because it's a mystery.
The reformed systematic theologian, Louis Berkhof, said:
"The Trinity is a mystery…It is especially when we reflect on the relation of the three persons to the divine essence that all analogies fail us and we become deeply conscious of the fact that the Trinity is a mystery far beyond our comprehension. It is the incomprehensible glory of the Godhead."
John Wesley said that "the trinity lies at the heart of all vital religion." He described our interaction with the trinitarian nature of God through the three experiences of God's grace: prevenient, justifying, and sanctifying grace. God created us with an innate longing to be in relationship with him (God the Father), our salvation comes through an experience of faith in God's gracious generosity toward us (God the Son), and we grow in our ability to live faithfully as the Spirit empowers us (God the Holy Spirit). God is three persons ("persons" being another inadequate linguistic expression), each of the three persons is always fully God, but God is One. Our experience of God’s grace is part of the mystery that confounds and amazes us at the same time. We can't explain it, but our experience makes it believable.
This coming Sunday is Trinity Sunday, and we'll celebrate God as Father, Son, and Holy Spirit or, if you prefer, as Creator, Redeemer, and Sustainer. I can't guarantee you'll come away with a better understanding of the Trinity, but we'll at least come away knowing that our God, who is mysterious and majestic, still wants to come alongside us as our friend and our guide.