Translation
So then, tongues are a miraculous sign,
Go to footnote numbernot to those who believe, but to the unbelieving; but prophecy is not for the unbelieving but to those who believe.
Paraphrase
So we see that the proper use of the gift of speaking publicly in an unknown language serves as a miraculous sign to convince those who do not yet believe in Jesus. In contrast speaking God’s truth and showing how to apply it to life is not intended to help those who do not yet believe, but those who do believe and are ready to obey.
Footnotes
1
The word I have rendered “miraculous sign” carries with it the implication that it must be something miraculous in order to be a sign or a confirmation or authentication. It emphasizes the end purpose which exalts the one giving the sign. It is always something that mere man cannot do, cannot replicate, and cannot take credit for.
HOW DOES THIS VERSE FIT WITH THE REST?
Here the comparison is between proper public tongues and prophecy. Public tongues (similar to what happened on Pentecost), is for unbelievers because it is intended to convince them to believe in Jesus. In contrast, prophecy (exhorting or admonishing about one’s spiritual condition) is for believers because it assumes one is ready to obey.
The need for the miraculous is made clear by the use of the word which does not mean simply “a sign,” but rather “a miraculous sign.” Satan’s counterfeit has eliminated the miraculous, enabling men and women to control the expression of the “gift” without having to depend on God’s spirit to do what mere man cannot do. Therefore, such action is not a gracious gift of the Holy Spirit.