There exist numerous versions of gospels in this world--people consider various things as their good news. The older son in the parable and the Pharisees (who are represented by the older son) had their own versions of the gospel, and it was different than the gospel that Jesus presented. To them, the gospel of Jesus was threatening to their version of the good news; it was a seriously dangerous gospel. If this is where we are, we will have to make a choice whether to embrace His life-giving danger or to keep holding onto the false gospel this world presents.