The children of Israel rebelled against the Lord by not entering the promised land because of unbelief. This unbelief was a result of not “knowing” God’s ways. Here in Hebrews it says:
7Therefore, just as the Holy Spirit says,
TODAY IF YOU HEAR HIS VOICE, 8DO NOT HARDEN YOUR HEARTS AS WHEN THEY PROVOKED ME, AS IN THE DAY OF TRIAL IN THE WILDERNESS, 9WHERE YOUR FATHERS TRIED ME BY TESTING ME, AND SAW MY WORKS FOR FORTY YEARS. 10“THEREFORE, I WAS ANGRY WITH THIS GENERATION, AND SAID, ‘THEY ALWAYS GO ASTRAY IN THEIR HEART, AND THEY DID NOT KNOW MY WAYS’; 11AS I SWORE IN MY WRATH, ‘THEY SHALL NOT ENTER MY REST.'”
Hebrews 3:7-11 Emphasis is mine
Then in Hosea chapter 13, it says;
4Yet I have been the Lord your God since the land of Egypt; and you were not to know any god except Me, for there is no saviour besides Me. 5I cared for you in the wilderness, in the land of drought. 6As they had their pasture, they became satisfied, and being satisfied, their heart became proud; therefore they forgot Me.
Hosea 13:4-6 (NASB 1995) emphasis is mine
The sons of Eli were called worthless men because they did not know the Lord
Now the sons of Eli were worthless men; they did not know the Lord
1 Samuel 2:12
1 Chronicles 28, King David urges his son, Solomon to “know” the Lord and seek the Lord so that God will not reject him
“As for you, my son Solomon, know the God of your father, and serve Him with a whole heart and a willing mind; for the Lord searches all hearts, and understands every intent of the thoughts. If you seek Him, He will let you find Him; but if you forsake Him, He will reject you forever.
1 Chronicles 28:9
God speaks through the prophet Jeremiah, on numerous occasions, where the people of Israel strayed away from God because they did not know God, and they refused to know Him
“The priests did not say, “Where is the Lord?’ and those who handle the law did not know Me; the rulers also transgressed against Me, and the prophets prophesied by Baal and walked after things that did not profit.
Jeremiah 2:8
“For My people are foolish, they have not known Me. They are silly children, and they have no understanding. They are wise to do evil, but to do good they have no knowledge”
Jeremiah 4:22
“They bend their tongue like their bow, lies and not truth prevail in the land; for they proceed from evil to evil, and they do not know Me,” declares the Lord
Jeremiah 9:3
“Your dwelling is in the midst of deceit; through deceit they refuse to know Me,” declares the Lord
Jeremiah 9:6
God spoke through the prophet Micah
“But they do not know the thoughts of the Lord, and they do not understand His purpose; for He has gathered them like sheaves to the threshing floor.”
Micah 4:12
So, what does it mean to know the Lord?
“He pled the cause of the afflicted and needy; then it was well. Is not that what it means to know Me?”
Jeremiah 22:16
“… But let him who boasts boast in this, that he understands and knows Me, that I am the Lord who exercises lovingkindness, justice, and righteousness on earth; for I delight in these things,” declares the Lord
Jeremiah 9:24
Through the prophet Jeremiah the Lord spoke about what He was going to do to make it possible for people to know Him…
“I will give them a heart to know Me, for I am the Lord, and they will be My people, and I will be their God, for the will return to Me with their whole heart.”
Jeremiah 24:7