For Mark, all the signs are that he was thinking, as many other early Christians were in his day, of the term ‘God’s son’ as having at least four meanings. First, in the Old Testament Israel itself is ‘God’s son’ (Exodus 4.22; Jeremiah 31.9). Second – and this seems to be a primary meaning in the baptism story – it is the Messiah, Israel’s anointed king, who is ‘God’s son’ (2 Samuel 7.12–14; Psalms 2.7; 89.26–27). Third, as we just noted, ‘son of God’ was a regular and primary title taken by the Roman emperors from Augustus on. But fourth, looming up behind and beyond all of these was the sense we find in the very earliest Christian documents that all of these pointed to a strange new reality: that, in Jesus, Israel’s God had become present, had become human, had come to live in the midst of his people, to set up his kingdom, to take upon himself the full horror of their plight, and to bring about his long-awaited new world. The phrase ‘son of God’ was ready at hand to express that huge, evocative, frightening possibility, without leaving behind any of its other resonances. We can see this already going on in the writings of Paul. It is highly likely that Mark expected his first readers to have the same combination of themes in mind.