When Jesus was on the cross and the last thing He said was “it is finished.” He declared the battle tide had turned. The response that came from the Roman Centurion in Matthew 27:54 (Holman Christian Standard Bible)
54 When the centurion and those with him, who were guarding Jesus, saw the earthquake and the things that had happened, they were terrified and said, “This man really was God’s Son!”
Jesus statement had significance for them. During their battles, in amongst all the confusion in the intensity of battle, when men fighting for their lives they had no idea if they were winning or loosing on that they were fighting for their very lives.
Their commander the general would be positioned on a high point watch the battle unfold and when he saw the battle tide turn in their favor he would shout out in a loud voice “It Is Finished” This not only rallied the troops but gave them vision that they are not fighting in vain, that total victory was immanent.
Jesus declaration on the cross in John 19:30 (Holman Christian Standard Bible) When Jesus had received the sour wine, He said, “It is finished!” Then bowing His head, He gave up His spirit.
Jesus declared the battle had turned. While we are in the midst of battle we need to hear the cry of Jesus on the cross, take heart and fight until we see the victory achieved by His sacrifice.
Another insight is that just before His death Jesus received the sour wine. Just like Jesus to take the old sour wine just before His death. On His Resurrection He released the New wine on the day of Pentecost.
He took the bitterness of the Law and released the freshness of life in the Spirit of Faith and Grace.