Therefore the Lord was very angry with Israel, and removed them from His sight; there was none left but the tribe of Judah alone. 2 Kings 17:18

The year was 722 B.C. and for a little over 200 years the kings of Israel did evil in the sight of the Lord after the sins of Jeroboam.

The Bible best describes this downfall.

1. They secretly did against the Lord their God things that were not right.
2. They built for themselves high places in all their cities, from watchtower to fortified city.
3. They set up for themselves sacred pillars and wooden images on every high hill and under every green tree.
4. There they burned incense on all the high places, like the nations whom the Lord had carried away before them.
5. They did wicked things to provoke the Lord to anger.
6. They served idols, of which the Lord had said to them, “You shall not do this thing.”
7. God sent prophets saying, “Turn back to the Lord God” nevertheless they would not hear, but stiffened their necks, like the necks of their fathers, who did not believe in the Lord their God.
8. They rejected God’s statutes and His covenant that He had made with their fathers, and His testimonies which He had testified against them.
9. They followed idols, became idolaters.
10. They copied the policies of the nations around them.
11. They left all the commandments of the Lord their God, made for themselves a molded image and two calves, made a wooden image and worshiped all the host of heaven, and served Baal.
12. They caused their sons and daughters to pass through the fire.
13. They practiced witchcraft and soothsaying.
14. They sold themselves to do evil in the sight of the Lord, to provoke Him to anger.

God humbled His people by allowing an oppressing nation to take away their pride. Assyria invaded Israel and took the people captive – transporting a large portion of them away to foreign lands.
What a sad time for these people when it was totally preventable.
All they needed to do was to put away the wickedness against God and turn their hearts to serve God. That is, repent and live by faith exclusively for Him.
This is still the same requirement for the salvation of an individual or a nation.