In the first century, the apostles had been given the power (by the Holy Spirit) to speak languages they never learned fluently. The apostles also had the ability to impart this gift to others by laying their hands on them. The purpose of the tongues was so that men would believe the message of the apostles. The ability to speak in tongues was also given to Cornelius and his household (Gentiles) for the purpose of showing that God does not show partiality. Since the apostles have long been gone and the purposes for tongues were fulfilled in the first century, tongues are no longer necessary today. See also Miracles and Baptism of the Holy Spirit
they were all amazed and marveled, saying to one another,
"Look, are not all these who speak Galileans? And
how is it that we hear, each in our own language in which we
were born? Parthians and Medes and Elamites, those dwelling in Mesopotamia, Judea and Cappadocia, Pontus and Asia, Phrygia and Pamphylia, Egypt and the parts of Libya adjoining Cyrene, visitors from Rome, both Jews and proselytes, Cretans and Arabs -- we hear them speaking in our own tongues the wonderful works of God." So they were all amazed and perplexed, saying to one another, "Whatever could this mean?"
those of the circumcision who believed were astonished, as
many as came with Peter, because the gift of the Holy
Spirit had been poured out on the Gentiles also. For
they heard them speak with tongues and magnify God.
Then Peter answered, "Can anyone forbid water, that
these should not be baptized who have received the Holy Spirit
just as we have?" And he commanded them to be baptized in the name of the Lord. Then they asked him to stay a few days.
when Paul had laid hands on them, the Holy Spirit came
upon them, and they spoke with tongues and
prophesied. Now the men were about twelve in all.
|1 Corinthians 13:8-10
never fails. But whether there are prophecies, they will fail;
whether there are tongues, they will cease;
whether there is knowledge, it will vanish away. For we know in part and we prophesy in part. But when that which is perfect has come, then that which is in part will be done away.
|1 Corinthians 14:5,6
||I wish you all spoke with tongues,
but even more that you prophesied; for he who
prophesies is greater than he who speaks with tongues, unless
indeed he interprets, that the church may receive
edification. But now, brethren, if I come to you
speaking with tongues, what shall I profit you unless I speak
to you either by revelation, by knowledge, by prophesying, or
|1 Corinthians 14:22,23
||Therefore tongues are for a
sign, not to those who believe but to
unbelievers ; but prophesying is not for unbelievers but for those who believe. Therefore if the whole church comes together in one place, and all speak with tongues, and there come in those who are uninformed or unbelievers, will they not say that you are out of your mind?