"In responding to the Pharisees' complaint that Jesus is receiving and dining with sinners (Luke 15:2), Jesus tells three parables-the lost sheep, the lost coin, and the prodigal son (Luke 15:4-32). The implication is that Jesus is doing what the Old Testament says God does: he is a shepherd who welcomes home repentant sinners (Ezek. 34:11; Ps. 103:8-13). (Incidentally, the Pharisees are represented by the complaining older son in the parable of the prodigal son. The Pharisees, like the older son, mistakenly think they deserve the father's gifts because of their good works. So this parable not only affirms the deity of Christ but also teaches that salvation is a free gift of God that cannot be earned, only accepted.)"
Norman L. Geisler and Frank Turek, I Don’t Have Enough Faith to be an Atheist, p. 343
Norman L. Geisler and Frank Turek, I Don’t Have Enough Faith to be an Atheist, p. 343