God was in Christ, reconciling the world unto himself. 2 Cor. 5:19.
Both Jesus and the Father were involved in the atonement together. God suffered when Jesus suffered. God was there at the cross, even though Jesus was unable to sense His presence. That's why Paul says that "God was in Christ, reconciling the world unto himself." God could not change His law, but He sacrificed Himself in Christ.
Have you ever wondered why, if God loved the world so much, He didn't come Himself? Why did He send His Son? If you are a parent, you probably don't need to ask that question. The father suffers more when he sees his son suffer. Haven't you ever been by the bedside of a loved one, someone who was suffering pain, and wished before God that you could trade places with the patient? It is much harder to watch. God died too, in a sense. Away with the pagan idea that God was angry and that Jesus was appeasing Him. They both suffered together.
Jesus took our place. His death was not incidental. It wasn't just another martyrdom. Jesus suffered the horror of the second death in your place and in my place. This is what broke His heart and made the physical pain hardly felt. I am thankful that He was wounded for our transgressions, bruised for our iniquity, aren't you? I'm thankful that He is a God of justice, because it means that we can have security forever. And I'm thankful that He is a God of love, and that His justice did not destroy His mercy.
The sacrifice of Jesus is full and complete. There is pardon for every person who will respond to His invitation and come to Him for rest. It is not enough to come once, but we must come again today, and every day, and fall at His feet in repentance and humility, accepting anew of His death in our place. As we do this, and continue to do this, we are assured of life eternal, because He paid the penalty for the wages of sin for us. He died so we don't have to die. Because He lives, we can live forever, if we will only accept His merits on our behalf. No work of man can add to the fullness of the salvation provided. As we see His loving acceptance, our hearts will respond in love to Him, and He will work in us to accomplish all that He has in mind for us--our complete recovery from the penalty, the power, and the presence of sin.