Luke 15 is one of the most unique chapters in the Gospels in that it consists of three memorable parables: the Lost Sheep, the Lost Coin, and the Prodigal Son. Many commentators locate these three parables (Luke 15) within a larger section of Luke that asks the question “who will participate in the reign of God?” (13:10-17:10). The section includes the foundational formation of the disciples – but often via the encounter with the Pharisees in which the assumptions of right relationship with God are put to the question. The Pharisees and others in the Jewish religious leadership assume folks such as tax collectors and sinners are outside the “faithful remnant” that awaits the return of the Messiah. At issue is the question of fellowship in the community of God’s people. Each encounter in this larger section seems to be an opportunity to form the disciples (and anyone who would listen) in the understanding of the reign of God.
The setting for teaching about this fellowship is so often the meal setting where questions of boundaries and community play out in terms of admission, honor, and hospitality. So often in this section the characters within the pericopes and parables are those who should attract respect and honor according to the conventional wisdom, yet within the parables are casualties of a reversal of values and misfortunes: “For behold, some are last who will be first, and some are first who will be last” (13:30). Joel Green outlines the reversal sayings as follows:
Central to participation in the kingdom is the position of the poor and marginalized. Jesus’ teaching in chapters 14 and 16 (which includes the parable of Lazarus and the rich man) regarding the importance of welcoming into one’s homes those who live on the margins of society – “the poor, the crippled, the lame, and the blind” (25:24; cf. 25:32; 26:30) – underscores the central question raised in 15:1-32.
Beyond the poor and marginalized, one should also be aware that one should not neglect the category of sin when asking this same central question. This broad category would also include those considered “lost.” In Jesus’ time there were four categories of sinners: physical, racial, social, and moral. One can see the physical category in the story of man born blind (John 9) that highlights the belief that his blindness was due to either his sin or the sin of his parents. The racial aspect can be seen in the attitude towards foreigners because they did not observe the Law (e.g., Gentiles and Samaritans). The social category applied to tax collectors. The moral category can be seen in the attitude towards money lenders (usury), divorcees, and prostitution – to name a few. Because Jesus sits and eats with them, he too is accused of being a sinner and empowered by Satan.
The gospel text of Luke 15 immediately follows section highlighting the reversals in the Reign of God (13:10-14:35). Luke presents three parables that have a common theme: the joy of finding what was lost or recovering one who was estranged (the lost sheep, the lost coin, and the lost son). These parables follow easily upon the extended section on the reversals of the kingdom because they respond to the Pharisees’ grumbling over Jesus’ practice of eating with outcasts.
Culpepper  notes that although the three parables share a common theme, the first two are paired while the third, which is more elaborate, balances the first two. The first two parables each begin with a question, “which one of you” (tis anthrōpos ex hymōn; v. 4), and “what woman” (tis gynē; v. 8). The third parable tells the story of “a certain man” (anthrōpos tis, v. 11). The common themes that link the parables are evidenced in the repetition of the terms “lost” (apollymi) and “found” (heuriskō) in the three parables:
The lost sheep
“and losing one of them” (v. 4)
“and go after the lost one until he finds it?” (v. 4)
“And when he does find it” (v. 5)
“I have found my lost sheep” (v. 6)
The lost coin
“and losing one” (v. 8)
“searching carefully until she finds it?” (v. 8)
“And when she does find it” (v. 9)
“I have found the coin that I lost” (v. 9)
The lost son
“he was lost, and has been found” (v. 24)
“he was lost and has been found.’” (v. 32)
In the parables, what was lost belonged to the owner from the start, but in both stories the owner expends diligent effort to recover the one lost possession. The theme of joy and celebration also recurs in all three parables:
- “joy” (vv.5, 7); “rejoice” (v.6),
- “rejoice” (v. 9), “rejoicing” (v. 10);
- “celebrate/celebration” (vv. 23–24, 32), “feast (v.29), “rejoice” (v. 32).
Although admittedly, the parable of the “Prodigal Son” leaves us in suspense, not knowing if the older son will join the celebration.