James McGrath, John’s Apologetic Christology, pp 77-79.
“The Johannine conflict with `the Jews’ over Christology was not about Jesus performing divine functions per se. If Jesus was God’s appointed, subordinate, obedient agent, then he could clearly do such things legitimately. The problem is that `the Jews’ do not recognize Jesus as God’s agent. In their view, he is an upstart, one of a number of messianic pretenders and glory-seekers to appear on the scene during this period of Jewish history. If Jesus is the Messiah, then his actions are legitimate, because he is God’s agent: this helps explain why John continues to summarize the key focus of his Christology in terms of belief that Jesus is the Messiah or Christ, even when he is discussing issues relating to Jesus’ exercise of divine prerogatives and functions. John’s aim is to demonstrate that the behavior and characteristics of Jesus are those of an obedient son and agent. Jesus does not seek his own glory, but that of the one who sent him. John is seeking to respond to Jewish objections by highlighting the aspects of Jesus’ person and work which make clear that he is God’s agent and sent one.
The issue is therefore not `equality with God’ per se, but whether Jesus makes himself equal to God. God could appoint agents, who would represent him and bear his full authority (examples include Moses, the judges and various principal angelic figures). It was only when someone who had not been appointed by God tried to put himself on a par with God (like Adam, Pharaoh or the king of Babylon in the Jewish Scriptures) that equality with God became problematic and even blasphemous; and it was into this latter category that `the Jews’ placed Jesus.
[So] the Johannine conflict with `the Jews’ did not concern a supposed abandonment of Jewish monotheism on the part of the Johannine Christians. The Fourth Gospel never mentions the oneness of God in a polemical manner, and affirms it on one or two occasions in passing (John 17.3; also 5.44). Rather, the issue is whether Jesus is an agent carrying out God’s will and purposes, or a blasphemer who is seeking glory and power for himself in a manner that detracts from the glory due to the only God.”