"Then [Note: This event answers to the "immediately" of Matt. 24:29, and suggests the next major event on God's calendar] there will be [supernatural] signs [evident] in the sun and moon and stars. And on earth [there will be] distress among nations; they will be perplexed by the roaring of the ocean's churning waves. [Note: Probably this is figurative language for highly agitated conditions on earth].