An endowment of God's power ... to be witnesses ....
Baptism in the Holy Spirit is the specific event that introduces the believer to the ongoing process of living a Spirit-empowered life. Although speaking in tongues is the outward sign of Spirit baptism, it is designed by God to be much more than evidence. Paul tells us its a sign to the unbeliever. Subsequent speaking in tongues brings enrichment to the individual believer when employed in private prayer (
1 Corinthians 14:4) and to the congregation when accompanied by the interpretation (
1 Corinthians 14:6,25).