Q: What is the primary purpose for the baptism in the Holy Spirit? Is it to speak in tongues or to perform miracles? Is it to get goosebumps and fall over?
A: NO – Jesus gave his disciples the reason. Shortly before his ascension he instructed the disciples to wait in Jerusalem for the promised baptism in the Holy Spirit:
Acts 1:8 'But you will receive power when the Holy Spirit comes on you; and you will be my witnesses in Jerusalem, and in all Judea and Samaria, and to the ends of the earth.'
So the primary reason for the baptism in the Holy Spirit is that we may receive power to be witnesses worldwide i.e. evangelism and missions.