At one time the Israelites declared their faith in God and held him in high honor -- they obeyed his commandments and teachings -- but then they fell away from their faith, turning to false idols -- turning away from God -- and turning to sin. And so God brought judgment -- sometimes a "destroying angel" that killed several thousand Israelites at a time. Sometimes that judgment was famine and disease. Other times that judgment was enslavement to enemy nations.
The Old Testament records the repeated rise and fall of the Israelites. When they followed God they were strong and blessed. When they turned from God and refused to turn back -- even after God sent prophets to warn them -- God would again bring judgment.
America is a lot like ancient Israel.
A few decades ago people throughout the country worshiped and followed God based on the Bible -- maybe that describes you and others you know. Today many people though have turned their backs on God, rejecting the Christian faith, to either embrace unbelief and atheism or to simply believe in a God that they can mold in their minds to suit their personal beliefs. The Bible would call this an "idol" or "false god".
Most Americans have created a false God in their minds and even a "different Jesus"; the Bible warns against worship of a "different Jesus". A different Jesus results when a person does not believe in Jesus as he's portrayed in the Bible.
We see that warning fulfilled in the world today on a massive scale; for example, churches (such as the Evangelical Lutheran Church of America) accepting homosexual clergy, a clear violation of the Bible (the ELCA has churches across America).
What about our schools? Elementary schools and middle schools have removed Jesus from Christmas songs -- even more so in just the last decade. The next time you're at a child's Christmas recital at school you'll likely notice that the songs they're singing are a lot different than what may have been sung in schools just a few years back or when you were growing up.
Everything will fall.
The Day of the Lord (we're talking serious planet changing wrath) is on the horizon.