...in First Corinthians 14 verses 21 and 22, “In the law it is written, With men of other tongues and other lips will I speak unto this people; and yet for all that will they not hear me, saith the Lord. Wherefore tongues are for a sign, not to them that believe, but to them that believe not…”

Paul is saying that the principle for the “how and why” of New Testament tongues is taught in the Old Testament. So, in order to understand what these languages were in the early New Testament church, we must go back and study them in their Old Testament usage.

God spoke of or used foreign languages or “unknown tongues” five times in the Old Testament. The first time is in Genesis chapter 11. God had instructed Noah, his sons and their descendents to “replenish the earth” (Gen 9:1). Because they intentionally disobeyed, God judged them by confusing their languages so that they could not understand each other (Gen 11:7).

The next time we read of them is found in Deuteronomy 28. The first 13 verses of this chapter describe the various blessings associated with obeying the command in verse one. In verse 15 we are given another promise, a promise of God’s curse if Israel does not believe or listen to God. Verse 49 of this chapter says that one of the curses that will identify God’s displeasure with Israel is the invasion of “a nation whose tongue thou shalt not understand.” This is no blessing. In fact, if Israel had believed and obeyed God, this foreign language power would not have fallen upon her.

The third time we see tongues mentioned in the Old Testament is found in Isaiah 28. The first 13 verses describe abominable and wicked practices of disobedience. In the middle of this prophecy Israel is warned once again that she will know that God has judged her by the presence of rulers speaking “another language” in her cities and streets (v. 11). Isaiah 10:5 identifies the country God is going to use to do it as Assyria. Notice please that this sign was not going to be sent because God was pleased. It was a sign of judgment for unbelief.

Isaiah chapter 33 is a very encouraging portion of Scripture. Read from verse one all the way down through verse 19. In verse 19 we read a wonderful promise given to those who believe and obey God, “Thou shalt not see a fierce people, a people of a deeper speech than thou canst perceive; of a stammering tongue, that thou canst not understand.” Here we see happily that the judgment of tongues will not occur when God’s people believe Him and obey His commands.

The final time tongues appears in the Old Testament is in the book of Jeremiah. Jeremiah suffered greatly at the hands of his own people. He was persecuted for speaking the truth. In chapter five verses one through fifteen we read of horrible unbelief, sin and wickedness. In verse 12 the people sound much like they do today, “They have belied the Lord, and said, It is not he; neither shall evil come upon us; neither shall we see sword nor famine.” Verses 14-15 speak of God’s judgment once again, “Wherefore thus saith the Lord God of hosts…Lo, I will bring a nation upon you from far…a nation whose language thou knowest not, neither understandest what they say.” Here again God uses the presence of another tongue as a sign to His people that they are being judged. Had Israel listened, repented, and walked in God’s ways, no invading army would have come and no foreign language would have been heard in their land.

In the Old Testament foreign (unknown) tongues were a judgment sent from God to Israel for unbelief. Understanding this (and Paul says we must), we have our starting point for understanding the New Testament doctrine of tongues.

So, how does the idea of ‘unbelief’ (not believing God) carry over to our understanding of “tongues” in the New Testament?

Did the nation of Israel believe that our Lord and Saviour Jesus Christ was God in the flesh, the Messiah of Israel? No. They rejected Him. The tongues of Acts chapter two were real, spoken languages (cf. vv. 4, 6, and 8) that came upon Israel to indicate that they were being judged for their unbelief. Jews from all over the Roman Empire were in Jerusalem to celebrate the Passover. They were witnesses to confirm that the sounds were not babbling, but indeed a spoken language – their language from home – a language the “locals” couldn’t speak – but yet they were speaking. The judgment against Israel for her unbelief had begun. (The “this” and “that” in verse 16 does not refer to tongues, but the outpouring of the Holy Spirit of God. We know this because twice in two verses (17 and 18) we are referred to the Holy Spirit. Remember, Joel chapter two never mentions tongues.)

God wanted Israel to love and be a blessing to all nations (Genesis 18:18). They were to “declare His glory among the heathen, his wonders among all people” (Psalm 96:3). Israel was specifically commanded not to “abhor an Edomite” nor “an Egyptian” (Deuteronomy 23:7-8), but they did! In fact, they hated all Gentile “dogs” and refused to even speak to a Samaritan (John 4:9).

Watch what is happening as Peter remembered the part of Joel’s prophecy that spoke about “all flesh” (Acts 2:17), but then needed a vision from Heaven – repeated three times – before he would go to a Gentile (Acts 10:9-17). And when Peter did arrive at Cornelius’ house, he still said that it was unlawful for him to be there! (Acts 10:28) Remember our key verse for understanding tongues? “Wherefore tongues are for a sign, not to them that believe, but to them that believe not…” (1 Cor 14:22). Peter was not believing.

In Acts 10 tongues was a sign to Peter and the other Jews that “believed not” that salvation was also for the Gentiles. In the same manner it took tongues to convince the Apostles and brethren in Judea that Gentiles could be saved (Acts 11:18). In every case (both Old and New Testaments), without fail, tongues were a sign of unbelief.

In 1 Corinthians chapter 14 there are seven rules that govern speaking in tongues. I would encourage you to read the chapter and identify all seven rules for yourself. Notice especially verse 37, “If any man think himself to be a prophet, or spiritual, let him acknowledge that the things that I write unto you are the commandments of the Lord.”

Thus, as far as the Bible teaches, tongues were simply foreign languages. Their emphasis was on the unbelief of the day (not faith or salvation). And we are also told that at some point the need for tongues would end (1 Cor 13:8).