Speaking in tongues is the sound heard when someone is filled with the Holy Spirit. It is the initial external evidence of being filled with the Holy Spirit. 
Speaking in tongues:
- accompanied the baptism of the Holy Spirit on the day of Pentecost.
- accompanied receiving the Holy Spirit throughout the book of Acts.
- is a prayer language to speak to God.
- is praying in the spirit.[4,5]
- is a sign that follows believers.
- is one of the gifts used in the church.
- builds up our faith.
Believers are strongly encouraged to pray ‘in the Spirit’. By doing so we are built up in faith, we pray more effectively, and God is able to keep us in perfect peace.
Being filled with the Holy Spirit is an experience that provides each of us with personal evidence of the existence and goodness of God.
Other subjects in this series:
- What must I do to be saved
- Water baptism
- The Holy Spirit
- Speaking in tongues
- Bible prophecy
- The return of Jesus Christ
 John 3:1-10, Acts 2:1-18
 Acts 2:4
 Acts 10:44-48, 11:13-17, 19:1-6
 1 Corinthians 14:2
 1 Corinthians 14:14-18
 Mark 16:17
 1 Corinthians 12:10, 14:26-27
 Jude 20
 Romans 8:26-27
 Philippians 4:6-7