Follow the way of love and eagerly desire gifts of the Spirit, especially prophecy. 2 For anyone who speaks in a tongue does not speak to people but to God. Indeed, no one understands them; they utter mysteries by the Spirit.3 But the one who prophesies speaks to people for their strengthening,encouraging and comfort (I Corinthians 14:1-3 NIV)
In the passage above, the Apostle Paul points out the practical superiority of the gift of prophecy over the gifts of tongues. The gift of prophecy, as used in the Bible, simply refers to a God-given ability to speak God’s commandments to others. This could come in the form of a vision warning about the future, or, as I believe is much more common in our day of a completed canon, though a Spirit-inspired understanding of the word of God. The gift of prophecy is a practically important gift, because the one who prophesies speaks to people for their strengthening, encouraging, and comfort. This gift is vital in the church because it helps edify and build up other believers.
The gift of tongues, however, is a much more personal gift. This gift, as used in this passage, seems to denote an ability to speak in some sort of supernatural language. This gift is not apparently given primarily for public worship, but for the strengthening of a personal relationship with God. Anyone who speaks in a tongue does not speak to people, but to God. Indeed, no one understands them, they utter mysteries of the spirit. This gift, if it genuinely exists today, is probably usually given to someone to be used in their private prayer life. The purpose of this gift is clearly NOT to be publicized for self-glorification. We must be careful that our awe with this mysterious gift does not inspire us to fake possession of it. Certainly it is a very easy gift to fake, since no one besides the speaker usually understands what is being said. People who are eager to brag about this ability are probably the least likely to have genuinely experienced it. I would think that God would usually give this gift to the person who has the incredible maturity and wisdom to keep it secret when necessary. God, after all, does not exalt an arrogant heart, but a humble one.