As far as verses 1-19, Paul talks to the Corinthians about the spirtual gifts of tongue and prophecy. There are many churches today that don't believe this chapter to be relevant today and therefore do what Paul instructs against. First of all, he mentions that all should pursue love and and earnestly desire the spiritual gifts- but especially the gift of prophecy. When someone speaks in tongue, the language is unknown and the Holy Spirit is speaking through them. (vs. 2-4: For one who speaks in a tongue speaks not to men but to God; for no one understands him, but he utters mysteries in the Spirit. On the other hand, the one who prophesies speaks to people for their upbuilding and encouragement and consolation. The one who speaks in a tongue builds up himself, but the one who prophesies builds up the church.) Most people who speak in tongue do not even know what they are saying. When this is done out loud infront of others, Paul instructs someone to interpret the tongue. This is where Paul says it is better to prophesy. If someone speaks in tongue, but no one interprets, how is anyone to know what is said? What's the point? (vs 6-9: Now, brothers, if I come to you speaking in tongues, how will I benefit you unless I bring you some revelation or knowledge or prophecy or teaching? If even lifeless instruments, such as the flute or the harp, do not give distinct notes, how will anyone know what is played? And if the bugle gives an indistinct sound, who will get ready for battle? So with yourselves, if with your tongue your utter speech that is not intelligible, how will anyone know what is said? For you will be speaking into the air.) If there is no one with the power to interpret, let them not speak out in tongue, but pray it between himself and God. (vs.28: But if there is no one to interpret, let each of them keep silent in the church and speak to himself and to God.) Otherwise, if a visitor enters the church, they might not be confused, but hear the voice of God. (vs. 23-25: If, therefore, the whole church comes together and all speak in tongues, and outsiders or unbelievers enter, will they not say that you are out of your minds? But if all prophesy, and an unbeliever or an outsider enters, he is convicted by all, he is called to account by all, the secrets of his heart are disclosed, and so, falling on his face, he will worship God and declare that God is really among you.) Although prophecy is more beneficial for the believer, it can be used to convict the unbeliever. Whereas when a tongue is spoken without interpretation, no one understands it and therefore serves no purpose but to edify the one who spoke it. That is why Paul says, "The one who prophesies is greater than the one who speaks in tongues, unless someone interprets, so that the church may be built up."
When spiritual gifts are practiced in an orderly way- the way the Bible instructs, God is most glorified and people are most edified. Verse 23 says, "For God is not a God of confusion but of peace."
This topic can be very uncomfortable for some, especially if you have never heard tongues spoken properly. I remember about six years ago, when I heard tongues being done in an unorderly fashion, and I got very angry! It was the first time I had ever heard it spoken, and it just didn't sit right with my spirit. I prayed and prayed about it. My husband and I confronted the church about the order of worship, described here in this chapter, and eventually things were done differently. A few weeks after the change, God empowered me to pray in tongues. It was very odd and awkward at first, but to this day I still practice praying in tongue. If you have never experienced this, or may even be in disbelief- ask God, like I did. Maybe He will enable you to speak also- maybe He will allow an opportunity to hear it spoken in a godly way. Maybe then, you will believe- like I did.
Father in Heaven, forgive us for our unbelief. I pray for those who are uncomfortable with these gifts would have their minds changed by the power of the Holy Spirit. Lord, that You would allow them to experience these gifts practiced in an orderly way or that you would empower them with the gifts themselves. Thank you for speaking through Paul who explained these things well that we might understand it. Amen.