Lightning here may point to the great cosmic signs that will mark the coming of the Messiah (see Matthew 24:29–31; 1 Thessalonians 4:13–18). The focus is on how easy the lightning is to see, not how suddenly it comes. Jesus probably shared these teachings to prevent early excitement about the end of time (1 Thessalonians 4:13–5:10; 2 Thessalonians 2:1–12).