But you have come to Mount Zion, to the heavenly Jerusalem, the city of the living God. You have come to thousands upon thousands of angels in joyful assembly. Hebrews 12:22

This verse is in stark contrast to the preceding verses where scenes about God giving Moses the Ten Commandments on Mount Sinai are described in terrifying ways. These types of passages cause some to conclude that God in the Old Testament is harsh and severe while God in the New Testament is full of mercy and compassion.

However, even in ancient times, God was full of mercy and compassion. The law and punishments God outlined to Moses seem severe and harsh because God was seeking to teach his people his holiness and justice. Every sin is worthy of the death penalty (Ezekiel 18:4 & 20). Any time someone didn’t die because of their sin they were being shown mercy. Punishments weren’t generally carried out to their full extent because God kept on showing mercy (eg. David and Bathsheba should have been stoned). God was looking forward to the day when Jesus would take upon himself the entire penalty for sin.

When someone experiences God’s punishment like the sudden deaths of Uzzah, Nadab, Abihu, Ananias and Sapphira, we are surprised because we take God’s mercy for granted. Yet these incidents serve as reminders that every sin is worthy of the death penalty. They are reminders of how much mercy we’ve received. There are many examples of God’s mercy throughout the Old Testament. Countless times God warned his people before he reluctantly sent them into exile, God forgave Nineveh much to Jonah’s displeasure (Jonah 4:2), Ruth was included in God’s people even though she was a Moabite (Deuteronomy 23:3).

God doesn’t change. He is still merciful and compassionate.