After a disrespectful address, the older son boasted of what he had done for his father and than blamed him for not giving him more. Clearly he felt that the father"s response should reflect justice rather than grace. He was counting on a reward commensurate with his work (cf. Matthew 20:12). This hardly reflects a loving relationship. [source][source][source]
"He hasn"t stayed home because he loved his father, but because working in his fields was a way to get what he wanted." [1][source]
Wiersbe pointed out parallels between the prodigal"s coming to his father and the sinner coming to God through Christ. The prodigal was lost ( Luke 15:24); Jesus said, "I am the way." The prodigal was ignorant ( Luke 15:17); Jesus said, "I am the truth." The prodigal was dead ( Luke 15:24); Jesus said, "I am the life" ( John 14:6). [2][source]
The older son refused to acknowledge his brother as his brother since he had so dishonored his father. By calling him his father"s son he was implying that the father shared his younger son"s guilt. Everyone in this chapter experienced joy except this elder brother. [source][source][source]
"The proud and the self-righteous always feel that they are not treated as well as they deserve." [3][source]