Why did Jesus say, "It is finished"

Don’t try to figure out how to forgive yourself. Jesus did that for you. Accept His forgiveness and let the Cross be your reminder of His love for you. It’s all Jesus! If your interested the cross necklace or earrings we have lots of designs we created as a reminder of Gods word at shieldsofstrength.com We make them and hundreds of other designs as a reminder of Gods word. John 19: 28-30 After this, Jesus knowing that all things were now accomplished, that the scripture might be fulfilled, saith, I thirst. Now there was set a vessel full of vinegar: and they filled a spunge with vinegar, and put it upon hyssop, and put it to his mouth. When Jesus therefore had received the vinegar, he said, It is finished: and he bowed his head, and gave up His Spirit.