The disciples were full of grief (Gr. lype, cf. John 16:20-22) because they did not realize how good it would be for them when the Holy Spirit came to indwell them. Really it was to the disciples" advantage (Gr. sympherei) that Jesus should leave them. Consequently Jesus proceeded to give them more information about what His coming would mean for them. Some of the benefits of the new covenant that Jesus ratified by His death, into which all believers entered at Pentecost, required the indwelling presence of God"s Spirit ( Jeremiah 31:33-34). [source][source][source]
Some Christians wish that they could have lived during Jesus" earthly ministry and accompanied Him around Palestine hearing His teachings firsthand and beholding His miracles with their own eyes. This would have been a treat, but Jesus here clearly affirmed that believers would be better off after the Spirit"s coming than they were before. [source][source][source]
"It is important to note that the Spirit comes to the church and not to the world. This means that He works in and through the church. The Holy Spirit does not minister in a vacuum. Just as the Son of God had to have a body in order to do His work on earth, so the Spirit of God needs a body to accomplish His ministries; and that body is the church.... The Spirit does not "float" in some ghostly way up and down the rows of a church building, seeking to win the lost. The Holy Spirit works through the people in whom He lives." [1][source]