What does Acts 7:55 mean?
Stephen is facing a furious mob bent on murder, but his attention is on Jesus. There is a difference between being notably "full of the Holy Spirit" and being indwelt by the Holy Spirit. All Christ-followers are permanently indwelt by the Holy Spirit (John 14:17). Being truly "filled with" the Holy Spirit means a total yielding of our thoughts and actions (Ephesians 5:18). Given our fallible human nature, this filling of the Holy Spirit doesn't usually last, but it is a normal state for Stephen (Acts 6:3, 5).One of the crimes Stephen is accused of is that he is continuing Jesus' plan to destroy the temple (Acts 6:13–14). The charge is ridiculous, since the Sanhedrin knew Jesus was talking about His own body, not the actual temple (John 2:19–22; Matthew 27:40). The greater irony, however, is that Jesus was really crucified because He prophesied what Stephen is seeing: "And Jesus said, 'I am, and you will see the Son of Man seated at the right hand of Power, and coming with the clouds of heaven'" (Mark 14:62). It was those words that gave the chief priests, the elders, and the scribes justification in their own minds to take Jesus to Pilate (Mark 14:63–64).
There is a slight difference, however. Jesus said He will sit at God's right hand, but Stephen sees Him standing. To stand in someone's presence is to offer one's services. It seems Jesus is letting Stephen know that He is there for him.