The Day of Evil, the Evil Day, or the Wicked Day, [Greek:] τῇ ἡμέρᾳ τῇ πονηρᾷ, is described in Ephesians 6:13 as being a particular period in which the Apostle Paul encourages Christians to stand firm against the works of the Devil. Paul may have been referring to the Great Tribulation or a portion of time in it, such as when John's vision of the wild beast wages war with the holy ones.
Christian armor for the wicked dayEdit
- Ephesians 6:10-13
Finally, go on acquiring power in the Lord and in the mightiness of his strength. Put on the complete suit of armor from God so that you may be able to stand firm against the crafty acts of the Devil;
because we have a struggle, not against blood and flesh, but against the governments, against the authorities, against the world rulers of this darkness, against the wicked spirit forces in the heavenly places.
For this reason take up the complete suit of armor from God, so that you may be able to resist in the wicked day (τῇ ἡμέρᾳ τῇ πονηρᾷ) and, after you have accomplished everything, to stand firm.
And to that end stay awake, constantly making supplication in behalf of all the holy ones. (Ephesians 6:18b)
Wild beast wages war with the holy onesEdit
- Revelation chapter 13
 And it [that is, the dragon] stood still on the sand of the sea. And I saw a wild beast ascending out of the sea, with ten horns and seven heads, and on its horns ten diadems, but on its heads blasphemous names.  Now the wild beast that I saw was like a leopard, but its feet were like those of a bear, and its mouth was like a lion’s mouth. And the dragon gave to the beast its power and its throne and great authority.  I saw that one of its heads seemed to have been fatally wounded, but its mortal wound had been healed, and all the earth followed the wild beast with admiration. - John's Vision of the Wild Beasts (Revelation 13:1-3)
 And they worshipped the dragon because it gave the authority to the wild beast, and they worshipped the wild beast with the words: “Who is like the wild beast, and who can do battle with it?”  It was given a mouth speaking great things and blasphemies, and it was given authority to act for 42 months.  And it opened its mouth in blasphemies against God to blaspheme his name and his dwelling place, even those residing in heaven.  It was permitted to wage war with the holy ones and conquer them, and it was given authority over every tribe and people and tongue and nation.  And all those who dwell on the earth will worship it. From the founding of the world, not one of their names has been written in the scroll of life of the Lamb who was slaughtered. - (Revelation 13:4-8)
 Then I saw another wild beast ascending out of the earth, and it had two horns like a lamb, but it began speaking like a dragon.  It exercises all the authority of the first wild beast in its sight. And it makes the earth and its inhabitants worship the first wild beast, whose mortal wound was healed.  And it performs great signs, even making fire come down out of heaven to the earth in the sight of mankind.  It misleads those who dwell on the earth, because of the signs that it was permitted to perform in the sight of the wild beast, while it tells those who dwell on the earth to make an image+ to the wild beast that had the sword-stroke and yet revived. (Revelation 13:11-14)
 And it was permitted to give breath to the image of the wild beast, so that the image of the wild beast should both speak and cause to be killed all those who refuse to worship the image of the wild beast.  It puts under compulsion all people—the small and the great, the rich and the poor, the free and the slaves—that these should be marked on their right hand or on their forehead,  and that nobody can buy or sell except a person having the mark, the name of the wild beast or the number of its name.  This is where it calls for wisdom: Let the one who has insight calculate the number of the wild beast, for it is a man’s number, and its number is 666. (Revelation 13:15-18)
 If anyone has an ear, let him hear.  If anyone is meant for captivity, he will go into captivity. If anyone will kill with the sword, he must be killed with the sword. This is where it calls for endurance and faith on the part of the holy ones. (Revelation 13:9, 10)
 And a reed like a rod was given to me as he said: “Get up and measure the temple sanctuary of God and the altar and those worshipping in it.  But as for the courtyard that is outside the temple sanctuary, leave it out and do not measure it, because it has been given to the nations, and they will trample the holy city underfoot for 42 months. - John's Vision of the Two Prophets (Revelation 11:1, 2)
 I will cause my two witnesses to prophesy for 1,260 days (42 months) dressed in sackcloth.”  These are symbolized by the two olive trees and the two lampstands and are standing before the Lord of the earth.  If anyone wants to harm them, fire comes out of their mouths and consumes their enemies. If anyone should want to harm them, this is how he must be killed.  These have the authority to shut up the sky so that no rain may fall during the days of their prophesying, and they have authority over the waters to turn them into blood and to strike the earth with every sort of plague as often as they wish. (Revelation 11:3-6)
 When they have finished their witnessing, the wild beast that ascends out of the abyss will wage war with them and conquer them and kill them.  And their corpses will be on the main street of the great city that is in a spiritual sense called Sodom and Egypt, where their Lord was also executed on the stake.  And those of the peoples and tribes and tongues and nations will look at their corpses for three and a half days, and they do not allow their corpses to be laid in a tomb.  And those dwelling on the earth rejoice over them and celebrate, and they will send gifts to one another, because these two prophets tormented those dwelling on the earth. - (Revelation 11:7-10)