Apparently tongues is a sign for unbelievers.  What does that mean?  In context it can not mean that speaking in tongues is a gift that unbelievers will see and become saved.  The passage clearly states that if unbelievers see tongues without interpretation it is not going to help them.  People will think that those speaking in tongues are out of their minds.  In the Bible a sign is frequently a negative thing, an omen of sorts.  Tongues are a sign of judgement on the unbeliever who can not accept that this is a work from God.  It confirms their position on the outside of the people of faith.

1 Corinthians 14: 18-25

¹⁸I thank God that I speak in tongues more than all of you. ¹⁹But in the church I would rather speak five intelligible words to instruct others than ten thousand words in a tongue.

 ²⁰Brothers, stop thinking like children. In regard to evil be infants, but in your thinking be adults. ²¹In the Law it is written:
   “Through men of strange tongues
      and through the lips of foreigners
   I will speak to this people,
      but even then they will not listen to me,”^[f] says the Lord.

 ²²Tongues, then, are a sign, not for believers but for unbelievers; prophecy, however, is for believers, not for unbelievers. ²³So if the whole church comes together and everyone speaks in tongues, and some who do not understand^[g] or some unbelievers come in, will they not say that you are out of your mind? ²⁴But if an unbeliever or someone who does not understand^[h]comes in while everybody is prophesying, he will be convinced by all that he is a sinner and will be judged by all, ²⁵and the secrets of his heart will be laid bare. So he will fall down and worship God, exclaiming, “God is really among you!”

Questions

1. What does Paul accuse Corinthians of thinking like?
2. When tongues are used what will the people do according to the quotation?
3. What is the overall argument of this passage?
4. How do some Pentecostals reverse this teaching?
5. Are you looking for something sensible to communicate with unbelieving friends?  How would they react if you spoke in tongues?

Going Deeper

1. What does Paul claim to do more than the Corinthians?
2. How many intelligible words are worth how many words in a tongue?
3. For whom is prophecy?
4. What will the unbeliever say upon hearing prophecy?
5. What will the unbeliever do upon hearing prophecy?

Interpretation

1. Why would Paul boast about speaking in tongues?
2. If 10,000 can be translated myriad what does that tell you about the ratio 5:10,000?
3. Look at Isaiah 28:11.  then look at Isaiah 28:10 and the NIV footnote.  What does this tell you about why Paul is using this verse in light of verses 10 and 12?
4. In Isaiah are the tongues positive or negative?
5. Why does Paul imply that every unbeliever will be blown away by prophecy when that is clearly not the case in reality?

Application

1.  When might you boast about a spiritual gift?
2. If Paul uses hyperbole, what does that say about a ‘literal’ reading of some passages?
3. Listen to The Police http://www.youtube.com/watch?v=OGax9i8k2_U&feature=related How does this relate to Paul’s argument?
4. Should people speak in tongues for a while as they mature toward prophecy?
5. How might some Pentecostals try and claim that unbelievers should hear tongues?