Who is the “One God” in the Matt. 28:19 Baptismal Formula?
This is a fantastic article about this verse. Here is the summary:Conclusion
The evidence discussed in this article confirms that the phrase “in the name of” in Matthew 28:19 is not attempting to radically redefine how many persons constitute the One God of Israel. But how then should it be understood? A more reasonable answer draws upon the Hebraic principle of agency whereby one who comes “in the name of” someone comes “in the power of” or “in the authority of” that person.
The list given by Jesus is arranged in hierarchical order. The Father – that is, the One God of Israel – is the sole source of all power and authority. He permanently bestowed this upon Jesus at the exaltation, and Jesus then exerted it in the world by means of the Holy Spirit. Nothing about this arrangement of delegated authority requires the foreign notion that all three figures constitute the same being.
Moreover, rather than being perceived as a Triune formula, the Biblical and historical evidence unanimously indicates that Matthew 28:19 was originally understood as follows: “Go therefore and make disciples of all nations, baptizing them in the name of the One God and of the Son and of the Holy Spirit.”
Source: Who is the One God in Matthew 28:19? (thetrinityontrial.com)