In Luke 15 we find the well-known parable of the prodigal son. It is the third in a series of three Jesus spoke when tax collectors and sinners drew near to hear Him, and the Pharisees complained that He received and ate with them (15:1-2). He spoke the parable of the lost sheep to them (15:3-7) along with the parable of the lost coin (15:8-10), and then the parable of the lost or prodigal son (15:11-32). Each of the parables deals with something or someone that was lost, and then found. In each there is a call to rejoice that what was lost has been found. In the first two parables, the lost thing which was found is likened to a sinner who repents at whose repentance there is rejoicing in heaven. The third parable tells the story of a sinning son who repented, and the merry made by his father at his return.
The father in the parable represents God the Father Who graciously welcomes back into fellowship His erring children who repent. The younger son who lived in sin probably represents the sinners and tax collectors whom Jesus receives. The older brother who was angry that the younger son was made much of because he repented represents the Pharisees and scribes who complained that Jesus received and ate with tax collectors and sinners.
We must be like the father in the parable, ready to forgive. We must repent if we are partaking of the sinful actions or attitudes of either of the two sons.