Why is it important to distinguish the gospel of the kingdom from the gospel of the grace of God?

Les explains that many cannot comprehend there is a difference between the gospel of the kingdom and the gospel of the grace of God, but there is a vast difference, and when you understand that, the Bible loses a lot of its confusion. The gospel of the kingdom was being proclaimed during the time of Christ and Peter and the eleven. Later, the 144,000 sealed young Jewish men will go around the globe with the gospel of the kingdom, not the gospel of grace. By then the age of grace has ended, the church is gone, and there is no longer an invitation to join a local congregation. Instead, during the final seven years, they tell the world that the king is coming. Christ himself referred to his message as the gospel of the kingdom, because the king and his kingdom were about to come on the scene; Israel rejected that, the king was crucified, God raised him from the dead and called him back to glory to sit at the Father's right hand until his enemies should be made his footstool, until he returns to deal with Israel.