The Holy Spirit plays the most significant role in the life of the apostles. The Book of Acts of apostles explains more about the roles of the Holy Spirit in Chapters #2, # 4, # 8 and #10. In Chapter 1, Jesus told his disciple to stay in Jerusalem and wait for the Holy Spirit. There were three distinct functions of the Holy Spirit as Christ showed. First function was to convict the world of sin.
In Chapter 1 of the Book of Acts, there is a list of the roles that the Holy Spirit plays. Firstly, the Holy Spirit acts as a medium of communication between Jesus and his disciples. In addition, he helps the disciple to preach the God’s words to the people (1:5, 8; 2:1-4) and helps to guide the actions of the disciples.
Ethiopian eunuch was made by the Holy Spirit to beg Phillip to baptize him (Acts: 8:36). Also, the Holy Spirit has the power to baptize; it even made Paul to fall down and ask Lord of what should he do. (Acts: 9:6). The Philippian jailer, who was very aggressive towards Silas and Paul, was prompted by the Holy Spirit to beg for salvation and ask Paul and Silas what was to be done to deserve the salvation.
Acording to the Book of Acts, salvation is seen as the deliverance of the souls from the bondage of sin (#5:31). This means that when one is saved and baptized, he or she receives the salvation and becomes holy in the eyes of God. The holy nature of the Holy Spirit defines the salvation and the deliverance of the since is completed by Jesus.
What Jesus does is that he gives salvation from sins, which is way more important than just saving the human’s life. It is a power of Jesus to heal the people, so it is also his power to save people from death and getting into hell. The other parts of the Book of Acts tell us about how people receive salvation from Jesus.
References
The Acts of the Apostles by Luke Timothy Johnson, Daniel J. Harrington 1992. Pages 14-18
A Bible Handbook to the Acts of the Apostles by Mal Couch 2004. Pages 120-129
Reading Acts: A Literary and Theological Commentary on the Acts of the Apostles by Charles H. Talbert 2005. Pages 24-25