1 Corinthians 14:20–25

²⁰ Brethren, do not be children in understanding; however, in malice be babes, but in understanding be mature. ²¹ In the law it is written: “With men of other tongues and other lips I will speak to this people; And yet, for all that, they will not hear Me,” says the Lord. ²² Therefore tongues are for a sign, not to those who believe but to unbelievers; but prophesying is not for unbelievers but for those who believe. ²³ Therefore if the whole church comes together in one place, and all speak with tongues, and there come in those who are uninformed or unbelievers, will they not say that you are out of your mind? ²⁴ But if all prophesy, and an unbeliever or an uninformed person comes in, he is convinced by all, he is convicted by all. ²⁵ And thus the secrets of his heart are revealed; and so, falling down on his face, he will worship God and report that God is truly among you.

Commentary

Vs. 20 "Brethren, do not be children in understanding; however, in malice be babes, but in understanding be mature."

From babes in the faith, to mature believers in Christ, is where the Apostle Paul is wanting to lead the Corinthians, and us all too. Now to do that the Apostle Paul will explain to us the primary purpose the Spirit gift of tongues was given. 

Vs. 21  In the law it is written: “With men of other tongues and other lips I will speak to this people; And yet, for all that, they will not hear Me,” says the Lord.

The Apostle Paul now quotes from or paraphrases Isaiah 28:11-12. A prophecy given to the Jews so that God's people when they saw the Holy Spirit given sign of tongues languages (i.e. Acts 2), would receive the refreshing and the rest for themselves, that is only found by believing in the Lord Jesus Christ. 

Vs. 22 "Therefore tongues are for a sign, not to those who believe but to unbelievers; but prophesying is not for unbelievers but for those who believe."  

Tongues were first and foremost given as a sign too unbelieving Jews that God has fulfilled His Word concerning His Son, just as Isaiah, and the other prophets prophesied about His coming to them. Therefore tongues are not given as a sign to those who already believe, (here specifically the reference is too the Jews who believe), rather they are given as a sign to the Jews who do not. Similarly prophesying is not for unbelievers; that is those unbelieving Jews (or anyone else) who has already hardened their hearts to the Word and Revelation of God given them through it; rather prophesy is for those who already believe. For by it, both the individual believer and church collectively are edified (that is built up in their faith). 

Vs. 23 "Therefore if the whole church comes together in one place, and all speak with tongues, and there come in those who are uninformed or unbelievers, will they not say that you are out of your mind?"

The Apostle Paul now moves into the realm of the Gentiles, the realm where the Corinthians dwelt and were practicing their faith. Now there's no doubt that the Corinthians believed the Gospel and had a great zeal for God. Yet in their zeal for Him, they had let certain practices amongst themselves get out of hand. And so the Apostle Paul wants them to understand that tongues speaking, just like any other given Spirit gift, can do more harm than good if it is not properly exercised and governed. Therefore to demonstrate this to them, Paul now says to them, "Therefore if the whole church comes together in one place, and all speak with tongues, and there come in those who are uninformed or unbelievers, will they not say that you are out of your mind?" vs. 23 

Here the reference is primarily to the uninformed and the unbelieving Gentiles, who would know little or nothing of Isaiah's prophecy, or what had occurred at Pentecost in fulfillment of it. And so if they came into their assembly, and saw the whole assembly or congregation practicing tongues, of course they would think that they were all out of their minds, because they would have no context in which it should be framed, and thus they would leave having never heard the Gospel preached to them, which is great tragedy, because that is why the church exists, to forward the Gospel of our Lord and Savior Jesus Christ, and through it make disciples of Jesus Christ of all people everywhere. 

Vs. 24-25 ²⁴ But if all prophesy, and an unbeliever or an uninformed person comes in, he is convinced by all, he is convicted by all. ²⁵ And thus the secrets of his heart are revealed; and so, falling down on his face, he will worship God and report that God is truly among you.

Here the superiority of prophesy is again self-evident because through it God can not only teach and instruct those who are believers already (as in vs. 22), but He can as is being emphasized here is verses twenty four and five, bring conviction of ones sin to them through it, and thus bring about the unbelieving persons repentance, and hopefully their turning to God through Christ because of it. For often it's not until one becomes aware of ones own sin/s, and or sinful condition, and thus their separated state from God (Isaiah 59:2), that they than see their need for God, and thus truly open their hearts to God and receive Christ for themselves (John 1:12). And so having come under the conviction of God, they can now come into the salvation of God, and truly experience His saving grace for themselves through our Lord and Savior Jesus Christ. 

I don't know where your at today, but I know this that today is the day of your salvation. For you don't have to live under the conviction and coming judgment of all your sins, rather you can have remission of them all, the moment you repent and believe and thus receive the Lord Jesus Christ for yourself. Therefore if you would like to do that, confess to God that you have sinned against Him, and then ask the Lord Jesus Christ to come into your heart and life, to not only save you from your sins and transgressions (and thus the judgment to come), but also to change your person and life, and thus direct your person and life from now on. I you then believe and want to have remission of all your sins and everlasting life with Christ then pray this prayer: Dear Lord Jesus I believe that You suffered Crucifixion death so that I can have remission of all my sins and everlasting life. Therefore I now invite You Jesus into my heart and life to be my Lord and Savior, amen. 

Scripture Quotations
The New King James Version. Nashville: Thomas Nelson, 1982.