The glorious truths of God's Word and especially of The Gospel are attacked in every generation by the activities of false messiahs (Greek christos - "anointed one") and teachers whose words do not agree with the Bible. The first thing Jesus taught his disciples about the future is that there will be false Christs.

Now as He sat on the Mount of Olives, the disciples came to Him privately, saying, "Tell us, when will these things be? And what will be the sign of Your coming, and of the end of the age?" And Jesus answered and said to them: "Take heed that no one deceives you. For many will come in My name, saying, 'I am the Christ,' and will deceive many. - Matthew 24:3-5

Jesus also taught that during the Tribulation the problem of false teachers and prophets will be even worse:

Then many false prophets will rise up and deceive many. - Matt. 24:11 At that time if anyone says to you, 'Look, here is the Messiah!' or, 'There he is!' do not believe it. For false messiahs and false prophets will appear and perform great signs and wonders to deceive, if possible, even the elect. - Matthew 24:23-24

At the midpoint of the Tribulation (Revelation 13) an "unholy trinity" will impose a one-world government and one-world religion on the people. This evil trinity includes the Dragon (the Devil), the first beast (evil world dictator), and another beast, whom most prophecy scholars call "the False Prophet."

11 Then I saw another beast coming up out of the earth, and he had two horns like a lamb and spoke like a dragon. And he exercises all the authority of the first beast in his presence, and causes the earth and those who dwell in it to worship the first beast, whose deadly wound was healed. He performs great signs, so that he even makes fire come down from heaven on the earth in the sight of men. And he deceives those who dwell on the earth by those signs which he was granted to do in the sight of the beast, telling those who dwell on the earth to make an image to the beast who was wounded by the sword and lived. He was granted power to give breath to the image of the beast, that the image of the beast should both speak and cause as many as would not worship the image of the beast to be killed. He causes all, both small and great, rich and poor, free and slave, to receive a mark on their right hand or on their foreheads, and that no one may buy or sell except one who has the mark or the name of the beast, or the number of his name. - Revelation 13:11- 17

We will also occasionally list efforts by false religions, atheists, and even entertainment industries to erode the faith of Christians.