"When Jesus had received the sour wine, he said, 'It is finished,' and He bowed His head and gave up His spirit." ~John 19:30
Once everything the prophets had spoken about Him had been done, Jesus cried "It is finished!" bowed His head and died. With this statement, Jesus was saying that everything that needed to be accomplished for our salvation had been done. There is nothing left to be done. There is nothing for us to do. Jesus did it all!