John 16

7 Nevertheless I am telling you the truth: it is to your advantage that I go away, because if I do not go away the Enabler will not come to you, but if I do go I will send Him to you.*Jesus could only be physically present in one place at a time. The Holy Spirit can be in all believers all around the world all the time—clearly to our advantage.

8 "Now when He comes he will convict the world about sin and about righteousness and about judgment: 9 first about sin, because they do not believe into me;*Since to believe into Jesus is the only cure for sin, to reject Him is the ultimate sin—you lock yourself into the consequences = spiritual death.