You apparently are unacquainted with the reference material Hebrews is dealing with--they kept on disobeying God in the wilderness. That was their "unbelief". Their disobedience. All those who "believed" God, spoken of in Hebrews 11, were
DOING things God wanted.
Hebrews 11
8By faith Abraham, when called to go to a place he would later receive as his inheritance, obeyed and went, without knowing where he was going.
9By faith he dwelt in the promised land as a stranger in a foreign country. He lived in tents, as did Isaac and Jacob, who were heirs with him of the same promise.
10For he was looking forward to the city with foundations, whose architect and builder is God.
11By faith Sarah, even though she was barren and beyond the proper age, was enabled to conceive a child, because she considered Him faithful who had promised.
12And so from one man, and he as good as dead, came descendants as numerous as the stars in the sky and as countless as the sand on the seashore.
13All these people died in faith, without having received the things they were promised. However, they saw them and welcomed them from afar. And they acknowledged that they were strangers and exiles on the earth.
14Now those who say such things show that they are seeking a country of their own.
15If they had been thinking of the country they had left, they would have had opportunity to return.
16Instead, they were longing for a better country, a heavenly one. Therefore God is not ashamed to be called their God, for He has prepared a city for them.
17By faith Abraham, when he was tested, offered up Isaac on the altar. He who had received the promises was ready to offer his one and only son,
c 18even though God had said to him, “Through Isaac your offspring will be reckoned.”
d 19Abraham reasoned that God could raise the dead, and in a sense, he did receive Isaac back from death.
God tested them in the wilderness to see if they would keep His commands in His land--and they failed the test, so they never entered because of disobedience/unbelief. Belief is the first step of submission to God.