To the untrained eye Christian theology appears to border on nonsense. For example, Christians believe that the one God is three persons, each of whom is also God. You do the math. The questions are well rehearsed. Is Christianity illogical? Do Christians believe bald-faced contradictions? Did the church just invent these bizarre doctrines arbitrarily? Surely logic warrants skepticism.
Not so fast. As a Christian, I fully affirm that contradictions are false. If a skeptic brings out contradictions in my beliefs, I’ll modify or abandon them. What I won’t do, however, is crumble under an alleged contradiction. I want to know precisely what the problem is. So let’s talk about the Trinity. Why did the church spend centuries trying to articulate this admittedly complex doctrine?
It starts with first century Palestinian Judaism. In that context, Jesus and his followers believed that there was only one God and would worship none other. However, there is strong evidence that early Jewish believers nevertheless worshipped Jesus. For example, “the oldest Christian sermon, the oldest account of a Christian martyr, the oldest pagan report of the church, and the oldest liturgical prayer (1 Cor 16:22) all refer to [Jesus] Christ as Lord and God.”
How could faithful Jews worship Jesus without blaspheming their God? It’s important to realize that Jesus’ followers weren’t thinking about God in terms of omnipresence, omniscience, and omnipotence. They knew who God was better perhaps than what God is. Indeed, their God was the God of Abraham, Isaac, and Jacob who led them out of Egypt and slavery, etc.
They had simple tools to differentiate God from the rest of reality. When they applied these tools to Jesus, they recognized him as the God of Israel. For example, Jesus asserted divine authority by forgiving sins, adjusting the God-given Law, and performing miracles over nature. These functions, among others, were understood as unique to their God. Indeed, Jesus was ultimately condemned to death for putting himself in God’s place.
By recognized Jesus’ divinity and worshipping him, the early church faced a problem. How could they worship Jesus “with the worship due only to God”? Furthermore, Jesus clearly was not the same person as the Father (to whom he prayed). To make a long story short, the question was, how could Jesus, the Holy Spirit, and the Father each be fully God yet together count as one God?
Although Paul was aware of this problem, the only book in the Bible that begins to solve it is John’s gospel. Were early Christians irrational to worship Jesus as God while still intending to remain faithful to the God of Israel? It would seem that the early church had “tacit knowledge” of the Trinity and were only later able to articulate their beliefs precisely. One can know a truth without being able to explain it. Indeed, if “knowledge were confined to what could be explained, it would be impossible to search for fresh knowledge.”
A coherent model
What about today? Is the Trinity a coherent doctrine? Put on your thinking hat! Philosophers J. P. Moreland and William Lane Craig present a coherent model in their Philosophical Foundations for a Christian Worldview. They suggest that the Trinity is the only instance of the divine nature—i.e. there’s only one God. That’s because being triune is part of the divine nature.
Now, God the Father, for example, is not identical to the Trinity because he himself is not a Trinity. Rather, the Father is a part of (or a person within) the Trinity. To say that the Father is God, then, means that the Father is divine by virtue of his membership in the Trinity. The same can be said for the Son and the Holy Spirit. Therefore, we can easily say that there is one God in three distinct persons, each of whom is divine. No contradiction there.
The last issue is to check whether this is heretical. Moreland and Craig’s proposal requires that each member be a part of the Trinity (rather than the whole). They claim, “Nothing in Scripture warrants us in thinking that … each person of the Trinity is identical to the whole Trinity.” Nevertheless, they admit that their model conflicts with the Eleventh Council of Toledo (A.D. 675) and the Fourth Lateran Council, suggesting that those councils wrongly emphasize a controversial doctrine of divine simplicity.
But I’m sure the skeptic won’t mind if we break with tradition on this issue. After all, it’s in the name of logic. To summarize, the lesson here is that articulating beliefs takes time—perhaps even centuries. Learning how to express one’s tacit beliefs requires logic and patience. Christian beliefs are no different. At the end of the day, logic is the friend of anyone seeking after truth.
 Richard Bauckham, Jesus and the God of Israel : God Crucified and Other Studies on the New Testament’s Christology of Divine Identity (Grand Rapids, MI: Eerdmans, 2009), 2.
 J. P. Moreland and William Lane Craig, Philosophical Foundations for a Christian Worldview (Downers Grove, IL: IVP Academic, 2003), 577.
 Bauckham, Jesus and the God of Israel, ix.
 They saw in Jesus their unique Creator and “sovereign Ruler” who reveals himself through a “narrative identity,” who “will achieve his eschatological rule,” whose name is YHWH, who “alone may and must be worshipped,” and who “alone is fully eternal.” ibid., 233–234.
 Moreland and Craig, Philosophical Foundations for a Christian Worldview, 576.
 Bauckham, Jesus and the God of Israel, 150.
 When discussing the Holy Spirit, the common approach is to note that “if a second shares the divine nature, there should be no insuperable difficulties in a third doing so, too.” Robert Letham, The Holy Trinity: In Scripture, History, Theology, and Worship (Phillipsburg, NJ: P & R Pub, 2004), 69.
 Letham, The Holy Trinity.
 Ibid., 69.
 Ibid., 54–55.
 Moreland and Craig, Philosophical Foundations for a Christian Worldview, 590.
 Ibid., 591.
 Ibid., 593.