From Martin Luther's hymn, A Mighty Fortress Is Our God:
The Prince of Darkness grim, we tremble not for him; His rage we can endure, for lo, his doom is sure, One little word shall fell him.
That one little word? Cross
John 12:31 Now is the judgment of this world; now will the ruler of this world be cast out. 32 And I, when I am lifted up from the earth, will draw all people to myself.” 33 He said this to show by what kind of death he was going to die.
Col. 2:15 He disarmed the rulers and authorities and put them to open shame, by triumphing over them in him.
Heb. 2:14 ...that through death he might destroy the one who has the power of death, that is, the devil...
Mark 3:27 But no one can enter a strong man’s house and plunder his goods, unless he first binds the strong man. Then indeed he may plunder his house.
(HT: Doug Wilson, Heaven Misplaced)