I am a classical Pentecostal, independent of any particular Penteostal persuasion.
Did not God say He could and would use anyone to bring about His purposes. So, being witness to somethng of God is no guarantee the man who seems to bringing it in the Name Jesus is, of himself, of Jesus.
"And John answered him, saying, Master, we saw one casting out devils in thy name, and he followeth not us: and we forbad him, because he followeth not us. But Jesus said, Forbid him not: for there is no man which shall do a miracle in my name, that can lightly speak evil of me. For he that is not against us is on our part. For whosoever shall give you a cup of water to drink in my name, because ye belong to Christ, verily I say unto you, he shall not lose his reward."
Mark 9:38-41 (KJV)