We RARELY hear the full Gospel of the kingdom proclaimed to sinners (as Jesus preached and Paul proclaimed in Acts).
Yes, we should tell sinners to “turn from your sin and trust in Jesus Christ, and be saved.”
But we should also tell them WHY.
The Gospel of the Kingdom that is so often omitted in our Gospel proclamation, because, in my opinion, it is, sadly, an embarrassment for many Christians to talk about the second coming, is this:
Tell sinners they need to be saved because Jesus is returning to earth to punish his enemies and to bring real peace among the nations as he rules as the Davidic King.
That is the part of the Gospel that is often truncated. Christian, if you are ashamed of talking about the second coming of Jesus to sinners, then perhaps Jesus will be ashamed of you when he comes back.
Here is the Gospel of the kingdom in a nutshell:
“At that time the LORD will punish the heavenly forces in the heavens and the earthly kings on the earth. They will be imprisoned in a pit, locked up in a prison, and after staying there for a long time, they will be punished. The full moon will be covered up, the bright sun will be darkened; for the LORD of Heaven’s Armies will rule on Mount Zion in Jerusalem in the presence of his assembly, in majestic splendor.” (Isa 24:21–23)
Truly, these times of ignorance God overlooked, but now commands all men everywhere to repent, BECAUSE He has appointed a day on which He will judge the world in righteousness by the Man whom He has ordained. He has given assurance of this to all by raising Him from the dead” (Acts 17:30-31 emphasis added).