The title Vicar comes from the word vicarious. It Latin it is Vicarius Christi. Christ operates vicariously through his vicars.
We can see this clearly in the Acts of the Apostles. As Apostles, Peter first and then Paul, continue the word of Christ - raising the dead, healing the lame, curing the sick and preaching the good news. Luke even tells us this in the very first line of Acts of the Apostles.
In the first book, O The-oph’ilus, I have dealt with all that Jesus began to do and teach, (Acts 1:1)
Luke’s first book is his Gospel. Luke also wrote Acts of the Apostles. The Gospels are a record of what Jesus began to do and teach. Acts of the Apostles is a record of what the Apostles continued to do and teach with Jesus acting vicariously through them. Jesus began and the Apostles and their successors continue. Peter and Paul testify that everything they do is because of Jesus.
And Peter said to them, "Repent, and be baptized every one of you in the name of Jesus Christ for the forgiveness of your sins. (Acts 2:38)
But Peter said, "I have no silver and gold, but I give you what I have; in the name of Jesus Christ of Nazareth, walk." (Acts 5:6)
And this she did for many days. But Paul was annoyed, and turned and said to the spirit, "I charge you in the name of Jesus Christ to come out of her." And it came out that very hour. (Acts 16:18)
Everything they do is “In the name of Jesus.” Jesus acts in the world through the Apostles.
-Tim-