Speaking in tongues can be beneficial, but only if it is used as it is intended. But don't let the desire for it to overshadow the much greater gift --one that can be much more beneficial to the body of Christ-- that is prophesying.
Prophesying is speaking forth God's word. He spoke directly to prophets before Jesus was born. They in turn told others what He wanted them to say. Since that time, He gave us the Living Word --Jesus-- and His life and influence have been recorded in the written word. Now that we have God's written word --the Bible-- we are to speak forth what that it says.
In the past God spoke to our forefathers through the prophets at many times and in various ways, but in these last days he has spoken to us by his Son, whom he appointed heir of all things, and through whom he made the universe. The Son is the radiance of God's glory and the exact representation of his being, sustaining all things by his powerful word. (Hebrews 1:1-3)
Remember what we read previously in 1 Corinthians 14:21-22. The purpose of speaking in tongues is to tell the gospel of Jesus to unbelieving Jews. Then what is the purpose of speaking in tongues in an assembly of believers? If there happened to be an unbeliever in the midst, there might possibly be some benefit. But most people there --including the speaker-- won't be able to understand what is being said. According to Paul, it is much better if the body understands what is being said than to speak in tongues.
I thank God that I speak in tongues more than all of you. But in the church I would rather speak five intelligible words to instruct others than ten thousand words in a tongue. (1 Corinthians 14:18-19)
God still has a purpose for men to speak in foreign languages (tongues). Although it is misused in churches today, we aren't to forbid it. God will use it in the way He chooses; and that is to reach His people.
Did the word of God originate with you? Or are you the only people it has reached? If anybody thinks he is a prophet or spiritually gifted, let him acknowledge that what I am writing to you is the Lord's command. If he ignores this, he himself will be ignored. Therefore, my brothers, be eager to prophesy, and do not forbid speaking in tongues. But everything should be done in a fitting and orderly way. (1 Corinthians 14:36-40)
Paul had a special place in his heart for his country men, even to the point of being willing to give up his own salvation if it could save them. To help to fulfill that desire, Paul instructed us to not forbid communicating the gospel to those lost Jewish brothers through the supernatural use of foreign languages as it was at Pentecost those many years ago. There the gospel was understood by God-fearing Jews from every nation [speaking every language] under heaven. (Acts 2:5)