The people made God angry by not keeping the covenant they promised to keep, they became impatient, committed idolatry and fornication. God is a loving God and his anger is a righteous one that shows that something has gone wrong and must be corrected for the sake of survival. In God's sentence to destroy Israel and rise up a new nation through Moses shows me that for God nothing is impossible and that we did not choose God, but that He in his loving mercy chose us.God's anger is provoked when His Holiness is assaulted by the acts of rebellion. Gods anger doesnt go away it can be redirected or delayed,but it will express itself.God's justice is not an optional pruduct of His will. But an unchangeable principle of His very nature.(Ps.89:14)Righteousness and Justice are the foundation of your throne. Unfailing love and thruth walk before you as attendants.