The word vicarious is extremely important to our understanding of the atonement of Christ. The late Swiss theologian Karl Barth once said that, in his judgment, the single most important word in all of the Greek New Testament is the minuscule word huper. This little word is translated by the English phrase “in behalf of.” Barth was clearly engaging in a bit of hyperbole in making this statement, because many words in the New Testament are arguably as important or even more important than huper, but he was simply seeking to call attention to the importance of what is known in theology as the vicarious aspect of the ministry of Jesus.
He made satisfaction for our debt, our enmity with God, and our guilt. He satisfied the ransom demand for our release from captivity to sin. However, there is another significant word that is often used in descriptions of the atonement: substitution. When we look at the biblical depiction of sin as a crime, we see that Jesus acts as the Substitute, taking our place at the bar of God’s justice. For this reason, we sometimes speak of Jesus’ work on the cross as the substitutionary atonement of Christ, which means that when He offered an atonement, it was not to satisfy God’s justice for His own sins, but for the sins of others. He stepped into the role of the Substitute, representing His people. He didn’t lay down His life for Himself; He laid it down for His sheep. He is our ultimate Substitute.