These things must happen: This shows that times of trouble are part of God’s plan as he moves history toward its conclusion (see Matthew 24:7, 29–30; 2 Thessalonians 2:8–12).
the end: This might mean the end of a period (like in AD 70) or the end of human history as we know it (compare Matthew 24:13–14; see also 10:22; 13:39–40, 49).