Mercy is God’s withholding of the judgment we deserve because of the payment of Jesus. Mercy is only available from God because Jesus paid the penalty for our sins. He is our propitiation (Rom. 3:25; Heb. 2:17; 1 Jn. 2:2). He satisfied the righteous wrath of God against our sin, and did so willingly (John 10:18). Without the finished work of Jesus there would be no mercy for you and me.
Jesus is Immanuel, God with us (Isaiah 7:14; Matthew 1:23). In Jesus, the Father drew near to us and fulfilled the requirements of His own law. According to sacrificial law, the high priest was required to enter the Holy of Holies (beyond the curtain)—into the very presence of God—only by bringing the appointed offering. This offering was the blood of an animal that was judged in the place of the common sinner as well as the priest (see Hebrews 9:1-28).
The priest sprinkled the blood over the top of the Ark of the Covenant. But do you know what the lid of the ark was called? It was called the mercy seat (Lev. 16:14-15). God is holy, and man is not. So, every year, on the Day of Atonement, the people of Israel were reminded that they could only draw near to God because of His mercy. Jesus fulfilled Old Testament sacrificial law. He is the only acceptable high priest, and He is the Lamb of God. Jesus is the only priest who never had to bring an offering for His own sin, but only for the people whom He represents—believers in Christ.
God is free to withhold judgment from us only because He did not withhold it from Jesus. All glory and praise to our great Savior!