Here it is once more –that same 1 Corinthians passage. Notice that it states that spiritual gifts –including speaking in tongues– have one, and only one, purpose. They are for the common good of the body of Christ –not for the good of the one who has the gift.
Now about spiritual gifts, brothers, I do not want you to be ignorant … There are different kinds of gifts, but the same Spirit. There are different kinds of service, but the same Lord. There are different kinds of working, but the same God works all of them in all men. (1 Corinthians 12:1, 4-6)
Now to each one the manifestation of the Spirit is given for the common good. To one there is given through the Spirit the message of wisdom, to another the message of knowledge by means of the same Spirit, to another faith by the same Spirit, to another gifts of healing by that one Spirit, to another miraculous powers, to another prophecy, to another distinguishing between spirits, to another speaking in different kinds of tongues, and to still another the interpretation of tongues. (1 Corinthians 12:7-10)
All these are the work of one and the same Spirit, and he gives them to each one, just as he determines. (1 Corinthians 12:11)
In regard to speaking in tongues, the book of Joel (referenced in Acts 2) declares that God's people –the Jews–- have wandered away and through His Spirit He will bring them back. He will reach them with prophesy through people from all over –Jews and Gentiles– retelling the gospel message which had its climax at the resurrection. The Jews are mixed into the nations of the world and have adopted those languages. So the message needs to be told to them in the language that they understand.
Then Peter stood up with the Eleven, raised his voice and addressed the crowd: "Fellow Jews and all of you who live in Jerusalem, let me explain this to you; listen carefully to what I say. These men are not drunk, as you suppose. It's only nine in the morning! No, this is what was spoken by the prophet Joel: (Acts 2:14-16)
"'In the last days, God says, I will pour out my Spirit on all people. Your sons and daughters will prophesy, your young men will see visions, your old men will dream dreams. Even on my servants, both men and women, I will pour out my Spirit in those days, and they will prophesy. I will show wonders in the heaven above and signs on the earth below, blood and fire and billows of smoke. The sun will be turned to darkness and the moon to blood before the coming of the great and glorious day of the Lord. And everyone who calls on the name of the Lord will be saved.' (Acts 2:17-21)
Again, spiritual gifts are not just for the good of a particular individual or assembly of believers, but for the good of entire body of Christ. So if you come in contact with a group of believers that focuses its attention on practicing spiritual gifts, you might ask yourself: According to the Bible, are they really using or misusing those gifts?