"Why is sacrifice necessary? Doesn't God simply forgive whom he pleases?"
Those are thoughts about how we are redeemed that I have heard often enough. I think we as Christians have not given much thought to sacrifice in the ancient sense of the word, the sense in which something is killed as part of a religious ritual. We might mention that type of sacrifice in order to point out that we don't do that anymore. After all, how much thought should we give the old Temple sacrificial system when the Temple no longer stands and the final sacrifice -- God's own sacrifice, once, for all has been made. I have also heard the old sacrificial system denigrated as a barbaric scheme meant to appease a vengeful, bloodthirsty God. Because the topic can be embarrassing or awkward (though I think that it does not deserve to be), we do not often take a deep and steady look at it. The reason I pursue it is that it helps us understand Christ's sacrifice and our sacrifice.
In the ancient sacrifices, a man's sin might be atoned for by the death of an animal. If you picture this as only a transaction or an exchange, it makes little sense. As an exchange it is not only unfair to the victim, it also does nothing for the wrongdoer except some would say in a legal sense, if the laws were set up in such a way, but that is an artificial and arbitrary connection.
The sacrifices were a graphic reminder that sin necessarily brings death. Destruction and corruption are a basic part of what sin is, and death necessarily follows. We know that it is not the sacrificial victim but we ourselves who have deserved death. The sinner has no part in a sacrifice if the victim dies but the sinner remains hard-hearted and unchanged. We have a part in a sacrifice when we desire that our sin should die. We participate in the sacrifice by putting to death the part of ourselves that deserves to die, putting to death the wrong thoughts and desires, the corruption in our lives. The revulsion we feel towards the blood and death of the sacrfice, this revulsion is rightly directed to the sin. We die with the sacrifice; we participate by dying to sin ourselves. When we participate in the sacrifice in this way, it transforms us and purifies us. Forgiveness alone does not make us fit to be in the presence of God. The sin in us must die.
We remember Christ's sacrifice for us, the victim in our place. We also put to death our own sins and die with him. Death, then, is turned upside down; in Christ's death and resurrection, its destruction of evil restores us to newness of life.
Here is a trustworthy saying: If we died with him, we will also live with him. (2 Timothy 2:11)More is planned for a future post about how we are united with Christ's sacrifice not only in his death, but also in his resurrection.