But first the Gospel must be preached to all nations.
This word reveals the breadth of God’s saving plan. The destruction of the temple and the judgment of Israel do not mean the end of God’s plan, but a new stage of the Gospel’s spread among all nations. The good news of Christ must reach not only one people, but the whole world. The word “must” shows a divine necessity: the preaching of the Gospel is God’s established will. The disciples should not have feared the coming persecutions, but should have understood that their service is part of a worldwide mission. Even within His judgments, God carries forward the purpose of His mercy.