Matthew 24:23 Then if anyone says to you, 'Look, here is the Christ!' or 'There he is!' do not believe it. 24 For false christs and false prophets will arise and perform great signs and wonders, so as to lead astray, if possible, even the elect. 25 See, I have told you beforehand. 26 So, if they say to you, 'Look, he is in the wilderness,' do not go out. If they say, 'Look, he is in the inner rooms,' do not believe it. 27 For as the lightning comes from the east and shines as far as the west, so will be the coming of the Son of Man. 28 Wherever the corpse is, there the vultures will gather. 29 "Immediately after the tribulation of those days the sun will be darkened, and the moon will not give its light, and the stars will fall from heaven, and the powers of the heavens will be shaken. 30 Then will appear in heaven the sign of the Son of Man, and then all the tribes of the earth will mourn, and they will see the Son of Man coming on the clouds of heaven with power and great glory. 31 And he will send out his angels with a loud trumpet call, and they will gather his elect from the four winds, from one end of heaven to the other.
Jesus has instructed us concerning the times right before He returns so we will not be led astray or deceived by false christs or false prophets who perform great signs and wonders. Signs and wonders can be done by Satan and his powers of darkness. The Apostle Paul teaches us that the coming of the lawless one (a one world ruler called the antichrist) is by the activity of Satan with all power and false signs and wonders (2 Thessalonians 2:9). Christians are to make sure the message of anyone claiming to be a prophet is in accord with the truth of the Bible.
When Jesus comes a second time to establish righteousness world wide, He will come as clearly as lightening in a dark sky. All will know without a doubt when Jesus comes. He will come immediately after the great tribulation, after the darkening of the sun and moon, after the stars fall from heaven and the power of the heavens is shaken. Jesus, the Son of Man, will come in the clouds of heaven with power and great glory. He will send out His angels with a loud trumpet call and gather His elect (all who repented of their sin and believed the gospel) to Himself. Paul writes of this in 1 Corinthians 15:50-52 and 1 Thessalonians 4:13-18 (It is important to turn to these passages and read them.).
It is important that each of us know the Word of God so that we will not be led astray and deceived by false signs and wonders. It is imperative that we prepare as many people as possible for the second coming of Christ. If people have not repented of their sin and believed the gospel, they will not be gathered to be with Christ in a new heavens and earth when He comes. They will be gathered and thrown into the Lake of Fire (Revelation 21:8). Are you prepared for when Jesus returns? Are you preparing others?