Since the coming of the Holy Spirit was the climaxing of redemption, making redemption effective where it counts, Jesus took great pains to prepare the disciples for His --the Holy Spirit's --coming.  It is "His", for the Holy Spirit is not an impersonal influence, nor is He just a sense of fellowship when we His "body" (the church) comes together.  Nor is He an enthusiasm over ideas or causes--the Holy Spirit is a Person with whom we can commune, from whom we can draw resources, who can be the LIFE of our life.  The coming of the Holy Spirit inaugurates a new era in humanity----the era of the Spirit.