1 Corinthians 14:6
Now, brethren, if I come unto you speaking with tongues, what shall I profit you, except I shall speak to you either by revelation, or by knowledge, or by prophesying, or by doctrine?
Corinthians 14:5
I would that ye all spake with tongues but rather that ye prophesied: for greater is he that prophesieth than he that speaketh with tongues, except he interpret, that the church may receive edifying.
Ah...Paul might seem to contradict himself, and in the same chapter of I Corinthians. Read the entire chapter, though, and you'll see that there is no contradiction.
Paul doesn't forbid glossolalia...he merely says that it is not required of Christians. There is a big difference.
Some denominations believe that glossolalia is proof of salvation. Others dismiss it as nonsense. Paul, on the other hand, admits that it is a valid expression, but not required of Christians.
Quoting out of contex is rarely useful.
Check the Book of Acts, to understand what speaking in tongues really is. On the day of Pentecost there were people of many tongues there and once the Holy Ghost arrived, each person spoke in his own tongue and yet was understood by all. Clarity of communication not babble.