We know that Jesus, in saying “It is finished,” was announcing the completion of all he came to earth to do. Before he breathed his last, he gave the triumphal cry, which in Greek is “tetelestai” “Paid in full!” All the atoning work of the cross was completed. Jesus did not need to linger for another moment of agony, for all the sins of the world had been covered. He was free to leave behind his earthly ministry and begin his heavenly ministry.
To a lesser extent the same thing can be said of the death of the Christian. We are released from earthly bonds when our mission is completed. I remember Bill Gothard saying many years ago. “Until your work on earth is complete, God sees to it that you are invincible. Then he takes you to be with him when your earthly work is done.”