For the Bible-believer there is a way to check, namely, “What is the healer’s range of healings?” If a healer specializes in unseen ailments, that, within itself, is a red flag of warning. Remember that the miracles of Jesus and His apostles covered the full range of illnesses—“every disease and every affliction” (Matthew 9:35). That is because God was truly at work in supernatural ways. Remember, for God it is just as easy to cure the worst leprosy (in which body parts literally fall off) as it is to cure a headache. The complete range of undeniable miracles was part of God’s way of showing us His inspired messengers.
This matter of invisible miracles has many facets. For example, anyone can say that God is speaking to him in a special and direct way. That is similar to claiming to be a modern prophet or apostle. Because claims are so easy to make, they have a long history of abuse, from the past to the present.
And the LORD said to me: “The prophets are prophesying lies in My name. I did not send them, nor did I command them or speak to them. They are prophesying to you a lying vision, worthless divination, and the deceit of their own minds” (Jeremiah 14:14).
The diviners see lies; they tell false dreams and give empty consolation. Therefore the people wander like sheep; they are afflicted for lack of a shepherd (Zechariah 10:2).
How could people tell the difference between a true prophet and a false prophet? As seen in the case of Moses, God used genuine miracles to certify His inspired spokesmen. As seen in the case of the apostles, God certified them with the full range of healing powers.
[Jesus] called to Him His twelve disciples and gave them authority over unclean spirits, to cast them out, and to heal every disease and every affliction (Matthew 10:1).