“Wherefore I give you to understand, that no man speaking by the Spirit of God calleth Jesus accursed: and that no man can say that Jesus is the Lord, but by the Holy Ghost.”
King James Version (KJV)
12:3 Therefore - Since the heathen idols cannot speak themselves, much less give spiritual gifts to others, these must necessarily be among Christians only. As no one speaking by the Spirit of God calleth Jesus accursed - That is, as none who does this, (which all the Jews and heathens did,) speaketh by the Spirit of God - Is actuated by that Spirit, so as to speak with tongues, heal diseases, or cast out devils. So no one can say, Jesus is the Lord - None can receive him as such; for, in the scripture language, to say, or to believe, implies an experimental assurance. But by the Holy Ghost - The sum is, None have the Holy Spirit but Christians: all Christians have this Spirit.
1Co 12:3 No man speaking by the Spirit of God calleth Jesus accursed. How should they test those professing to speak by the divine Spirit? If a heathen priest professed to speak by the spirit and called Jesus accursed, he had not the Spirit of God. In times of persecution Christians were asked to say "Jesus Anathema". No man can say that Jesus is the Lord, but by the Holy Ghost. If one speaking by the spirit pronounced Jesus the Lord, he had the Holy Spirit. This confession from the heart is always moved by the Spirit.