Recently I was in a situation where a question was raised about the words in Matthew 28:18, "All authority in heaven and on earth has been given to me". The question was along the lines of this: "If Jesus is God, didn't he always have all authority? How can it then be given to him?" Or to put it more technically: "Since Jesus is one of the persons of the Trinity, and equally God, didn't he always have all authority, and so how can it be given to him? Or is he somehow inferior to the Father?" But perhaps sometimes our trouble is that we jump to one mystery--the Trinity--while forgetting the other one--the Incarnation. In Jesus both these mysteries intersect, and we have to be very careful about jumping to conclusions as we try to navigate doubly difficult terrain. There is a danger sometimes of downplaying the actual text of Scripture (and perhaps we can add in another mystery, that of Divine Inspiration), and instead resorting to our doctrinal assumptions of what the sacred text may be speaking about. And sometimes the answers may be found in remembering all the mysteries of the faith.
In the case of Matthew 28:18, I think John Calvin helpfully upholds the plain meaning of the text by rightly resorting to the mystery of the Incarnation rather than being overwhelmed by the Trinity. Listen to his comments, where he interprets Jesus' words as speaking about his authority in the Incarnation rather than his authority as God:
Yet let us remember that what Christ possessed in his own right was given to him by the Father in our flesh, or—to express it more clearly—in the person of the Mediator; for he does not lay claim to the eternal power with which he was endued before the creation of the world, but to that which he has now received, by being appointed to be Judge of the world. Nay, more, it ought to be remarked, that this authority was not fully known until he rose from the dead; for then only did he come forth adorned with the emblems of supreme King.
