The Berean

  Matthew 24:24

(24) For false christs and false prophets will rise and show great signs and wonders to deceive, if possible, even the elect. 

  Revelation 13:13-14

(13) He performs great signs, so that he even makes fire come down from heaven on the earth in the sight of men. (14) 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. 

  Matthew 7:22-23

(22) Many will say to Me in that day, "Lord, Lord, have we not prophesied in Your name, cast out demons in Your name, and done many wonders in Your name?" (23) And then I will declare to them, "I never knew you; depart from Me, you who practice lawlessness!" 

  Deuteronomy 13:1-5

(1) "If there arises among you a prophet or a dreamer of dreams, and he gives you a sign or a wonder, (2) and the sign or the wonder comes to pass, of which he spoke to you, saying, "Let us go after other gods"—which you have not known—"and let us serve them," (3) you shall not listen to the words of that prophet or that dreamer of dreams, for the LORD your God is testing you to know whether you love the LORD your God with all your heart and with all your soul. (4) You shall walk after the LORD your God and fear Him, and keep His commandments and obey His voice; you shall serve Him and hold fast to Him. (5) But that prophet or that dreamer of dreams shall be put to death, because he has spoken in order to turn you away from the LORD your God, who brought you out of the land of Egypt and redeemed you from the house of bondage, to entice you from the way in which the LORD your God commanded you to walk. So you shall put away the evil from your midst. 
New King James Version   Change Bible versions

In each case, Christ's admonition is that we should have a healthy skepticism of miracles because miracles may produce deception. It is not that the miracle does not occur. The more important point is, does it witness to the truth? Does it witness to the ultimate reality, the will of God?

In both Jesus' instruction in the New Testament (Matthew 24:24; 7:22-23; Revelation 13:13-14) and in Moses' teaching in the Old Testament (Deuteronomy 13:1-5), it is clear—regardless of the wonder done—if a person even implies that we are free to disobey God, the miracle is not a demonstration of God's truth. A miracle it was, but it does not validate God's truth.

We must be especially skeptical of those who say that they believe in keeping God's laws, and then turn right around and say that the Sabbath and holy days are no longer necessary and that "true Christians" can keep Christmas, Easter, Halloween, etc. But they "believe" that they are to keep God's laws! It is especially deceptive because so many of such people are really nice individuals.

— John W. Ritenbaugh