In John 20:28, Thomas beheld the resurrected Christ and famously exclaimed: “My Lord and my God!” One way to interpret this statement is to assume that Thomas was applying both titles to Jesus. Trinitarian apologists naturally choose this option, and further claim that Thomas was therefore identifying Jesus as YHWH God himself.
The Gospel of John is thought to contain the strongest evidence for the traditional view that Jesus Christ is the second member of a Triune God. From John’s famous prologue to the declaration of doubting Thomas, there appears to be a trove of prooftexts available to the Trinitarian.
In Deuteronomy 6:4, the passage that famously established Judaism as a monotheistic religion, Israel’s God Yahweh (YHWH) identifies himself as “One God.” In Malachi 2:10, this “One God” Yahweh is specifically identified as the Father. But what about the relationship of the “One God” to the prophesied Messiah?
In Romans 10:13, the apostle Paul reached the summit of a brilliant discourse on salvation by citing Joel 2:32 in the Greek Septuagint: “For, ‘everyone who calls upon the name of the Lord will be saved.’” The Septuagint substitutes the title “Lord” for God’s personal name, but Paul was surely aware that the original Hebrew instructs people to “call upon the name of YHWH” for salvation.