We should not think that just because someone performs miracles he must be from God. We may be surprised to see how often Scripture shows Satan’s workers using powers that seem miraculous. The magicians of Egypt were able to repeat some of the amazing things done by Moses. They changed wooden staffs into snakes, made water into blood, and produced frogs (Exodus 7:11, 22; 8:7). The difference was that they did these things “by their secret arts” and their powers proved, in the end, to be very inferior to God’s power in Moses. Deuteronomy warned of false leaders using “a sign or a wonder” that involved accurate forecasts.
If a prophet or a dreamer of dreams arises among you and gives you a sign or a wonder, and the sign or wonder that he tells you comes to pass, and if he says, “Let us go after other gods,” which you have not known, “and let us serve them,” 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 (Deuteronomy 13:1-3).
Under the Old Covenant, a prophet or a dreamer, found to be false, was put to death (Deuteronomy 13:5). Under the New Covenant, God’s people do not administer the death penalty; that is left to the Lord. Jesus Himself assures us that the judgement will see the condemnation of many miracle workers who used His name (Matthew 7:21-23). Why is He so strict? Because, in Satan’s hands, the deceptive power of miracles is great. The spiritual dangers are real, as Jesus warned in Matthew 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 (Matthew 24:24).