What many churches call "speaking in tongues" today is nothing like what the Bible records in the books of Acts and Corinthians. The miracle that occurred on the Day of Pentecost (Feast of Weeks) in A.D. 31 (Acts 2:4-8) was one of communication—apparently, in this case, not so much in the speaking as in the hearing. The Greek word translated "tongues" is glossa and means "languages." The miracle of "speaking in tongues" simply meant that every member of the audience could hear in his or her native tongue (language), regardless of what language the apostles spoke.
Also, some in the early Church, particularly in Corinth, had the ability to speak in different languages. Some people in Corinth were proud about their ability, having lost sight of the fact that spiritual gifts were to be used to serve others. Paul wrote chapter 14 of 1 Corinthians specifically to deal with this problem. Paul reminded the Christians in Corinth that speaking different languages was of no real value if an audience could not understand the words. He admonished them to concentrate more on understandable communication than on their linguistic abilities. All biblical examples stand in stark contrast to the type of "speaking in tongues" generally done today using an unintelligible language.
In other letters, Paul and John warn Christians not to be taken in by spiritual-appearing phenomena, indicating that demon spirits sometimes imitate spiritual gifts in an attempt to confuse people (1 Timothy 4:1; 1 John 4:1).
Vine's Complete Expository Dictionary of Old and New Testament Words in the article "Tongues" makes this comment: "There is no evidence of the continuance of this gift after apostolic times nor indeed in the later times of the apostles themselves" (page 636). Today God has blessed the Church with members who speak many languages, so apparently this gift is not currently necessary.
Some scriptures indicate that this gift may not be given again to Christians until shortly before the second coming of Jesus Christ. Peter, on the Day of Pentecost, referred to Joel 2:28-32 in explaining what was happening as a result of receiving the Holy Spirit on that day. But it seems this was a partial fulfillment of Joel and that the complete fulfillment will occur at Christ's second coming. This final fulfillment will also be accompanied by miraculous signs, perhaps including the ability to speak in tongues, or known languages, in order to preach the gospel in a final, powerful manner.
Based on the principles in 1 Corinthians 14, UCG does not encourage speaking in tongues, but encourages use of the other gifts and fruits of the Spirit (1 Corinthians 12-13; Galatians 5:22-23).
For More Information on the Holy Spirit, see Transforming Your Life: The Process of Conversion.