That is who God is. God is He who punishes for every sin in some way that is satisfactory to Him.
In the case of Adam and Eve, God punished them by keeping His promise that they will die if they eat of the fruit of the Tree of Knowledge.
God keeps His promises.
It is because God keeps His promises that God empowered Israel’s enemies, so that they can invade Israel and kill Israelites. The Book of Jeremiah clearly states that God intentionally strengthened Israel’s enemies so that they can invade Israel and kill the believers, which God wanted as divine punishment.
God wants to kill believers (Christians) when they go against the Holy Bible, such as supporting gay rights or tolerating transgender people in their towns, cities, state, or nation.
God is merciless against Christians who go against His Will. God not showing mercy is God’s essential nature when dealing with believers who intentionally stand against the Law of God.