Because they rebelled against Him after everything He had done them to care for them and to lead them in the way everlasting. Were the rebels blind and incapable of seeing God and obeying His commands? Absolutely not. They clearly saw and understood the works of God on their behalf, which angered God because their rebellion was wilful, not in ignorance.
Psalm 78
21 Therefore the Lord heard this, and was wroth: so a fire was kindled against Jacob, and anger also came up against Israel;
22 Because they believed not in God, and trusted not in his salvation:
Why does God send modern rebels against God to hell without excuse? Because when they knew God they still rebelled against Him.
Romans 1:21
Because that, when they knew God, they glorified him not as God, neither were thankful; but became vain in their imaginations, and their foolish heart was darkened.
Psalm 78
21 Therefore the Lord heard this, and was wroth: so a fire was kindled against Jacob, and anger also came up against Israel;
22 Because they believed not in God, and trusted not in his salvation:
Why does God send modern rebels against God to hell without excuse? Because when they knew God they still rebelled against Him.
Romans 1:21
Because that, when they knew God, they glorified him not as God, neither were thankful; but became vain in their imaginations, and their foolish heart was darkened.