The point of the story of the prodigal is not primarily about the prodigal. It is about the father's heart. "But while he was still a long way off, his father saw him and was filled with compassion for him; he ran to his son, threw his arms around him and kissed him" (Luke 15:20 NIV). This is the kind of Father you have. This is how he feels about you. This is the purpose for which Christ came.
But when the time had fully come, God sent his Son, born of a woman, born under law, to redeem those under law, that we might receive the full rights of sons. Because you are sons, God sent the Spirit of his Son into our hearts, the Spirit who calls out, "Abba, Father." So you are no longer a slave, but a son; and since you are a son, God has made you also an heir" (Gal. 4:4-7 NIV).
As George MacDonald explains, "The word used by St. Paul does not imply that God adopts children that are not his own, but rather that a second time he fathers his own, that a second time they are born—this time from above. That he will make himself tenfold, yea, infinitely their father" (Unspoken Sermons).
We begin to make the one most central, most essential shift in all the world, the shift Christianity is focused on, by at least beginning with the objective truth. How this plays out in our lives will come later. For now, there are things you must know. You are the child of a kind, strong, and engaged Father, a Father wise enough to guide you in the Way, generous enough to provide for your journey. His first act of provision happened before you were even born, when he rescued you through the life, death, and resurrection of our elder brother, Jesus of Nazareth. Then he called you to himself—perhaps is calling you even now—to come home to him through faith in Christ. When a man gives his life to Jesus Christ, when he turns as the prodigal son turned for home and is reconciled to the Father, many remarkable things take place. At the core of them is a coming into true sonship.