Testing the spirits
A final warning in the Bible concerns the problem of deciding whether someone has a revelation or a power from God or whether they are attempting to deceive others into believing that they are prophets or Apostles.
"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)
This warns us that it will sometimes be difficult to tell that the apparent miracles of a false teacher are not from God. Even in the first century there were false prophets among the followers of Jesus:
"Beloved, do not believe every spirit, but test the spirits to see whether they are from God, for many false prophets have gone out into the world." (1 John 4:1)
"But even if we or an angel from heaven should preach to you a gospel contrary to the one we preached to you, let him be accursed. As we have said before, so now I say again: If anyone is preaching to you a gospel contrary to the one you received, let him be accursed." (Galatians 1:8,9)
The warning of false prophets is very clear and is followed by an exhortation to be careful and to test the prophets who claim the Spirit of God to see whether they are telling the truth.
The tests that are given are tests of power, but mainly they are tests of teaching. In the Law of Moses there is a test for whether someone is really a prophet speaking for God or is a fake prophet speaking from their own mind.
"And if you say in your heart, ‘How may we know the word that the LORD has not spoken?’ — when a prophet speaks in the name of the LORD, if the word does not come to pass or come true, that is a word that the LORD has not spoken; the prophet has spoken it presumptuously. You need not be afraid of him." (Deuteronomy 18:21,22)
This is the test of the prediction. Anyone who claimed to speak words from God should be able either to specify a miracle and perform it or to predict a future event with accuracy. If the prophet - the person who claims that he is acting by the Holy Spirit - cannot make an accurate prediction, or is unable to perform a miracle, or is vague about what will happen, then they are not working by the power of the Holy Spirit.
However, this is not the only test, or even the most important test. The main test was whether the teaching of the prophet was the same as the teaching of the rest of Scripture.
"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 13:13)
This test is repeated in the New Testament. The first letter of John gives three tests for the teaching of someone who claims to have a revelation from God:
"By this you know the Spirit of God: every spirit that confesses that Jesus Christ has come in the flesh is from God, and every spirit that does not confess Jesus is not from God. This is the spirit of the antichrist, which you heard was coming and now is in the world already." (1 John 4:2,3)
This is the test of teaching about Jesus. Anyone who does not agree that Jesus came in full human nature is not from God. This includes the tendency to be tempted and the fact that Jesus had human limitations, including suffering.
The second test involves the teaching of the Apostles:
"We are from God. Whoever knows God listens to us; whoever is not from God does not listen to us. By this we know the Spirit of truth and the spirit of error." (1 John 4:6)
John here writes as a representative of the Apostles who were responsible for the writing of the New Testament (among other things). Someone whose teaching doesn’t agree with that of the Apostles is not from God. If they claim that they do come from God with a message from God, that message should be rejected.
This is the case no matter how important that person is, or how likely it seems to be that the person is from God. In Galatians 1:8 Paul tells us that we should even test an angel from heaven or an Apostle like Paul himself. The point is so important that he repeats it in the next verse:
"As we have said before, so now I say again: If anyone is preaching to you a gospel contrary to the one you received, let him be accursed." (Galatians 1:9)
The point here is that the real test of teaching is not the apparent credentials of the teacher, but the words of God as written in the Bible.