The disciples knew they had work to do and a mission to fulfill, and they knew they needed help in getting it done. They would face dangers, intellectual challenges, and personal weakness. For decades of dedication, they needed more than adrenaline — they needed the Holy Spirit. This is commemorated yearly in the Christian calendar with the day of Pentecost. See Pentecost — for the church today

Why does God call us to be his people? To declare his praises. Why does he give us the Holy Spirit? To be witnesses to Jesus Christ (Acts 1:8). The Holy Spirit empowers us to preach the gospel, to announce the good news that humans can be part of God's kingdom through his grace and mercy and through what Christ has done for us. See Pentecost — power for the gospel

Every Christian has a spiritual gift, and should be involved in some area of service. Every Christian should be using his or her gifts to serve others "for the common good" (1 Cor. 12:7; 1 Pet. 4:10). Often, we do not know our gifts until we have put them to use and seen whether we do well in that type of activity. See Spiritual gifts are given for service

Some churches emphasize the practice of speaking in tongues. They teach that every Christian should speak in tongues as evidence of receiving the baptism of the Holy Spirit. Other churches allow the practice of speaking in tongues, but do not encourage it. Still other churches forbid their members from speaking in tongues. What does the Bible say? See What the Bible says about speaking in tongues