Simple, says John Piper. Missions exists because worship doesn't. There is a disregard for the glory of God and a satisfaction in Christ among all peoples and cultures and nations on the globe. Paul hits it right on: For "THE NAME OF GOD IS BLASPHEMED AMONG THE GENTILES BECAUSE OF YOU," just as it is written (Rom 2:24). The ultimate problem in the world is that... The glory of God is not honored, The holiness of God is not reverenced, The greatness of God is not admired, The power of God is not praised, The truth of God is not sought, The wisdom of God is not esteemed, The beauty of God is not treasured, The goodness of God is not savored, The faithfulness of God is not trusted, The commandments of God are not obeyed, The justice of God is not respected, The wrath of God is not feared, The grace of God is not cherished, The presence of God is not prized, The person of God is not loved. That's the problem with the world that we live in. From Piper, Let the Nations Be