Some further thoughts on the idea that the prodigal son in Luke 15 should be identified as Jesus speaking about himself (following on from what I wrote here)...
The son finds himself in a place that represents the absence of God – slowly dying, surrounded by pigs. From this place, he returns to his father as one who has sinned against heaven and against his father, who is no longer worthy to be considered a son but hopes to be a servant, this time of his father (for he has already become a servant).
Instead, the father not only takes him back as a son, but elevates the younger son to a place of honour, putting upon him the best robe, a ring, and sandals – symbols of authority over the father’s entire estate – because he was dead and is alive again.
When Jesus took upon himself the sins of the world he became sin, cut off from God, experiencing death and descending to hell. Although he lived without sin, he died the greatest sinner of all, carrying everything that separates us from God and neighbour.
Now consider Philippians 2:5-11, where Paul draws on a very early hymn in praise of Christ:
“Your attitude should be the same as that of Christ Jesus:
Who, being in very nature God, did not consider equality with God something to be grasped, but made himself nothing, taking the very nature of a servant, being made in human likeness. And being found in appearance as a man, he humbled himself and became obedient to death - even death on a cross! Therefore God exalted him to the highest place and gave him the name that is above every name, that at the name of Jesus every knee should bow, in heaven and on earth and under the earth, and every tongue confess that Jesus Christ is Lord, to the glory of God the Father.”
Here is the one who made himself nothing, who became a servant, and died. And who God – the Father – exalted to the highest place, in order that everyone should acknowledge the Son...for this is how the Father has decided that he himself will glory, in honouring the Son.
That sounds to me like the same story, from two sides: the parable foretelling the story, and the hymn reflecting on it.
And Paul introduces the hymn by saying that our attitude should be the same as that of Jesus Christ. The prodigal son, who squandered his father’s resources on sinners, is our role-model.