When St Paul says that to be in Christ is to be a new creation, he cannot mean that God the Creator has looked at the work of his hands, judged that he had made a botched job of it, and decided to start all over again. The work God does in Christ is not a setting aside of our original creation in the image and likeness of God, so that another, better creation might take its place. It is exactly the same creation, but now the fullness of God's purpose is revealed in it.
It is not God who has botched his work of creating us in his own image and likeness; it is we ourselves who have done this, by our unwillingness to be created in that image and likeness. But, no matter what kind of a mess we have made of God's creative goodness to us, in Christ we can be as God always intended we should be, made in his own image and likeness. That is the new creation now offered to us.
The point is illustrated by the parable in today's gospel. The father in the parable does not change in his generous, indulgent, love towards his sons. But each of his sons, in his own different way, mistakes the giving of that love.
The younger son exemplifies the sin of Adam. Adam was lavishly provided for, and had been promised an even greater inheritance. But it was not enough. He wanted everything, and he wanted it at once. And by seizing it ahead of time he cut himself off from the loving, creative care of God. Just so, the younger son in the parable seized all his inheritance ahead of time, and cut himself off from the loving guidance of his father. Like the indulgent father in the parable, God allowed Adam the freedom to make a complete mess of all he had been given.
If we insist on our independence from God, if we try to escape his creative hands, we will never come to be in his image and likeness. All we will ever be able to become is what we can make of ourselves: and what we can make of ourselves will not be the image and likeness of God, but an image of our own manufacture, fit only for idolatry.
Another way of mistaking our relationship with God is by mistaking not his gift to us, but the giver of that gift. Here the problem is not that we make an idol of ourselves, but that we make an idol of God: making God in our image and likeness, rather than allowing God the freedom to be God, the freedom to make us in his image and likeness.
This mistake is exemplified by the elder son in the parable. He has supposed that his relationship with his father depends on rigid adherence to a contract. He will get his inheritance in return for many years of service, of unswerving obedience, and that is all. He knows all about duty, and nothing about love. And, as he is, so he supposes his father to be. Because there is no generosity in his own heart he is as hurt as he is surprised to discover the generosity in his father's heart.
The father is as just and generous to one son as he is to the other. But he can only be generous with his love if he is allowed to be himself. So it is with us in our relationship with God. Just as we cannot be made in the image and likeness of God if we withdraw ourselves from God's creative hands, so neither can God pour out his bounty on us if we refashion God in our own ungenerous image.
So it was that we had need of another son, not a fictional one, like the two sons in the parable, but a real one, the Son of God himself, who came to show to us, in his own person, both what God is really like, and what is the image and likeness after which we will be fashioned, if only we give God the freedom to do this.