Matthew 24
23"Then if anyone says to you, 'Behold, here is the Christ,' or 'There He is,' do not believe him.
24"For false Christs and false prophets will arise and will show great signs and wonders, so as to mislead, if possible, even the elect.
25"Behold, I have told you in advance.
26"So if they say to you, 'Behold, He is in the wilderness,' do not go out, or, 'Behold, He is in the inner rooms,' do not believe them.
2 Thess 2
1Concerning the coming of our Lord Jesus Christ and our being gathered to him, we ask you, brothers, 2not to become easily unsettled or alarmed by some prophecy, report or letter supposed to have come from us, saying that the day of the Lord has already come. 3Don't let anyone deceive you in any way, for (that day will not come) until the rebellion occurs and the man of lawlessness[a] is revealed, the man doomed to destruction. 4He will oppose and will exalt himself over everything that is called God or is worshiped, so that he sets himself up [lit: so as to seat hiself] in God's temple, proclaiming himself to be God.
2 Timothy 4
1In the presence of God and of Christ Jesus, who will judge the living and the dead, and in view of his appearing and his kingdom, I give you this charge: 2Preach the Word; be prepared in season and out of season; correct, rebuke and encourage—with great patience and careful instruction. 3For the time will come when men will not put up with sound doctrine. Instead, to suit their own desires, they will gather around them a great number of teachers to say what their itching ears want to hear. 4They will turn their ears away from the truth and turn aside to myths. 5But you, keep your head in all situations, endure hardship, do the work of an evangelist, discharge all the duties of your ministry.
Revelation 22:18-19
18I warn everyone who hears the words of the prophecy of this book: If anyone adds anything to them, God will add to him the plagues described in this book. 19And if anyone takes words away from this book of prophecy, God will take away from him his share in the tree of life and in the holy city, which are described in this book.