Eventually as you can see from the reading, his father went outside and tried to reason with him. From what he said to his father we can easily see what the problem was. It was jealousy. He was jealous because his father had never thrown a party for him and his friends. He was so jealous that it kept him from being thankful to God that his brother was back home safe. All he could see was that his brother didn’t deserve what he was getting.
Jealousy is one of the worse things you could have to deal with. When a person becomes jealous over another person, there is no way to reason with them. It seems like all reasoning and common sense takes flight. This trait has no place whatsoever in the life of a child of God. If you see it start to manifest in your life, nip it in the bud. Stop it before it gets to the point where it consumes you.