The Father serves the Son. The Son serves the Father.. The circle is the circle of servanthood." (my italics, p. 80, Darrell W. Johnson, Experiencing the Trinity)
I know some of my readers know their Trinitarian theology better than me, but I cannot think of a verse that would suggest that the Father serves the Son. Certainly, the Son glorifies the Father and the Father glorifies the Son (although even that is not simply circular I don't think). Also the Father gives (life) to the Son. But doesn't the Son obey the Father and not vice versa?
