Throughout the Bible, there is a seeming paradox: God is holy and just, but He is also loving and forgiving. God declares these things to be true about Himself in Exodus 34. He tells Moses that He is a “merciful and gracious God, slow to anger, abounding in steadfast love” (Exodus 34:6). But He also says that He will by no means clear the guilty (Exodus 34:7). We are left with the question: how can God be gracious, loving, and merciful, while also being a just, holy, fair judge of the guilty?

In Romans, Paul considers the answer to this question to be evidence of “the righteousness of God” (Romans 3:26). If God is truly righteous, how can He acquit the guilty? How can He forgive sin? How can He show pardon to sinners without violating His holiness (Lev. 19:2)? In other words, how can he be just and justify (i.e. declare righteous) sinners?

One might be tempted to believe that the answer comes in minimizing mankind’s sinfulness in light of God’s holiness. Maybe we really aren’t that bad after all. Maybe it’s no big deal for God to overlook our sins. But Paul doesn’t give us that option. He claims that all mankind falls short of the glory of God (Romans 3:23). So much so that everyone is without excuse (Romans 1:20). We are all sinners deserving judgment for not glorifying God and not giving thanks to Him (Romans 1:21). Furthermore, we cannot work our way into right standing with God (Romans 3:21-22). Thus, to simply overlook our sin would compromise God’s holiness. But He desires to save us. So how can He forgive us of ours sins and give us the righteousness we need while remaining righteous and just?

The answer comes in the person of Christ and is understood in the doctrine of substitutionary atonement. In Romans 3, after establishing that all fall short of God’s glory, Paul claims that all those who believe in Christ will be justified as a gift of God’s grace through the redemption which is in Jesus (Romans 3:24). God sends His Son to redeem us and justify us. In other words, to set us free from the penalty of and our slavery to sin (redemption), and to declare us righteous in His sight (justification). But how does He do that?

In the next verse, Paul tells us that God accomplishes this redemption and justification by giving His Son as an atoning sacrifice (Romans 3:25). The phrase atoning sacrifice implies that Christ’s death on the cross satisfied God’s righteous wrath against sin. By His sacrifice, He has atoned for our sin and has appeased the wrath of God. How? By standing in our place as our substitute, as if He was us.By taking the judgment of God that all of our sins deserve.

Peter describes it this way, “Christ also suffered for sins once for all, the righteous for the unrighteous, that He might bring you to God” (1 Pet. 3:18). Did you catch that? The righteous for the unrighteous. That’s substitution. The same truth is taught in 2 Corinthians 5:21,  “God made the one who did not know sin to be sin for us, so that in Him we might become the righteousness of God.” These passages teach that Jesus took the full punishment that we deserve for our sins as a substitute in our place in order that we might become righteous in Him.

Because of the cross of Christ, God remains just. He has judged sin. He has “by no means cleared the guilty” (Exod. 34:7). His Son was judged as the guilty party, who suffered it willingly in order to save us. He is, after all, “a merciful and gracious God” (Exod. 34:6). As a result, we are redeemed from the penalty and effects of sin. But God can also justify us, not only because our sins are forgiven, but because we are given the righteousness of Christ (2 Corinthians 5:21).

Here’s substitution in a nutshell: He takes our sin and the penalty for it. He gives us His righteousness and the reward of it.

That’s the amazing gift of substitution. It is the gift of God’s grace offered to all who have faith in Jesus (Rom. 3:24; 26). Because of Christ and His work, God remains just and can justify the one who has faith in Jesus.

That’s good news!