Yet in this thing ye did not believe the LORD your God,
2 Chronicles 20:20
In the morning they got up early and went out to the wilderness of Tekoa. As they were about to go out, Jehoshaphat stood and said, "Hear me, Judah and you inhabitants of Jerusalem. Believe in the LORD your God, and you will be established; believe in His prophets, and you will succeed."
because they did not believe God or rely on His salvation.
They despised the pleasant land and did not believe His promise.
the head of Ephraim is Samaria, and the head of Samaria is the son of Remaliah. If you do not stand firm in your faith, then you will not stand at all.
Watch out, brothers, so that there won't be in any of you an evil, unbelieving heart that departs from the living God.
And to whom did He "swear that they would not enter His rest," if not those who disobeyed?
So we see that they were unable to enter because of unbelief.
Now I want to remind you, though you know all these things: the Lord, having first of all saved a people out of Egypt, later destroyed those who did not believe;