I have written about this in the past.
Cessationism claims that the miracle gifts of the Holy Spirit were signs to authenticate the early church. And consequently the miracle gifts disappeared when the Apostles did. Continuationism says that all the gifts were for the church and that all the gifts of the Holy Spirit are still valid...
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Furthermore, tongues serve many practical functions.
Five Uses of Tongues
1) Personal prayer language (speaking to God) See Acts 1:5, 1 Corinthians 14:2 and Acts 19:6
2) Intercessory prayer language (prayer in the Spirit) See Romans 8:26
3) Congregational message (preferably with interpretation) 1 Corinthians 14
4) Worship language (singing in tongues) See 1 Corinthians 14:15
5) Evangelistic language (language of the hearers) Like the outpouring at Pentecost. See Acts 2
Here's another topic that emphasizes the importance of tongues.
Why hadn't the baptized believers in Samaria received the Holy Spirit? Just to be clear, I do not question whether the believers in Samaria had received the "indwelling" Spirit when they believed. They were missing something else. Acts 8:14-17 NIV When the apostles in Jerusalem heard that...
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What is the Baptism with the Holy Spirit
Luke 3:16 NIV
John answered them all, “I baptize you with[
a] water. But one who is more powerful than I will come,
the straps of whose sandals I am not worthy to untie.
He will baptize you with[
b]
the Holy Spirit and fire.
Acts 1:4-5 NIV
... “Do not leave Jerusalem, but wait for the gift my Father promised, which you have heard me speak about.
5 For John baptized with[
a] water, but in a few days you will be
baptized with[
b]
the Holy Spirit.”
Evidence of the Baptism with the Holy Spirit
Acts 2:4 NIV
All of them were filled with the Holy Spirit and began
to
speak in other tongues[
a] as the Spirit enabled them.
Acts 2:11 NIV
(both Jews and converts to Judaism); Cretans and Arabs—
we hear them
declaring the wonders of God in our own tongues!”
Acts 10:45-47 NIV
The circumcised believers who had come with Peter were astonished that
the gift of the Holy Spirit had been poured out even on Gentiles.
46 For they heard them
speaking in tongues[
a]
and praising God. Then Peter said,
47 “Surely no one can stand in the way of their being baptized with water.
They have received the Holy Spirit just as we have.”
Acts 19:6 NIV
When Paul placed his hands on them, the Holy Spirit came on them,
and they
spoke in tongues[
a]
and prophesied.