Manasseh was twelve years old when he began to reign - and he reigned for 55 years. The Bible says that "he did that which was evil in the sight of the LORD" - including building high places, worshiping the sun, moon and stars, child sacrifice, enchantments, wizardry and familiar spirits (what we would today call witchcraft), and idolatry. God sent Prophets to Manasseh and the people in an attempt to bring them back into true worship of the only true God - but he - and they - wouldn't listen. The recitation of his sins ends with the "shedding of innocent blood."
His son - Amon - followed faithfully in his father's footsteps. Amon killed by his own servants after just two years, and was replaced by his young son, Josiah, who was just eight years old when he began his reign.
Under the influence of Hilkiah and Shaphan, Josiah led the nation in a great reform. He tore down and completely destroyed the high places - stopped child sacrifice - and killed the priests that had led the people into idolatry. The Bible says - "Now before him there was no king like him, who turned to the Lord with all his heart, with all his soul, and with all his might, according to all the Law of Moses; nor after him did any arise like him." He was truly a man after God's own heart - who worked tirelessly to restore the nation to God.
"Nevertheless the Lord did not turn from the fierceness of His great wrath, with which His anger was aroused against Judah, because of all the provocations with which Manasseh had provoked Him. And the Lord said, “I will also remove Judah from My sight, as I have removed Israel, and will cast off this city Jerusalem which I have chosen, and the house of which I said, ‘My name shall be there.’" 2 Kings 23:26, 27
Sadly, Josiah's reforms were not enough to spare Judah from the judgement of God. God knew that the people had not changed their hearts - that they had not truly repented of the sins committed under Manasseh - and He knew that once Josiah was gone, they would go right back to doing the evil of his grandfather. The Land would once again run with the blood of the innocents, and judgement would come.
"In his days (Jehoiakim) Nebuchadnezzar king of Babylon came up, and Jehoiakim became his vassal for three years. Then he turned and rebelled against him. And the Lord sent against him raiding [a]bands of Chaldeans, bands of Syrians, bands of Moabites, and bands of the people of Ammon; He sent them against Judah to destroy it, according to the word of the Lord which He had spoken by His servants the prophets. Surely at the commandment of the Lord this came upon Judah, to remove them from His sight because of the sins of Manasseh, according to all that he had done, and also because of the innocent blood that he had shed; for he had filled Jerusalem with innocent blood, which the Lord would not pardon."
2 Kings 24:2-4
SO - just a few years after the great reforms of Josiah, the LORD brought judgement upon Judah because He would not pardon the shedding of innocent blood.
Jeremiah also spoke of the coming judgement - "they have forsaken Me and made this an alien place, because they have burned incense in it to other gods whom neither they, their fathers, nor the kings of Judah have known, and have filled this place with the blood of the innocents (they have also built the high places of Baal, to burn their sons with fire for burnt offerings to Baal, which I did not command or speak, nor did it come into My mind)" Jeremiah 19: 4, 5
The people of God had walked one step at a time into incredible wickedness, thinking that what they were doing was very religious. They had stepped into idolatry - then into sacrificing to their new gods - ending in the sacrifice of their own children - something so abhorrent that God says it never even crossed His mind! They had gone so far away from true worship - into a lifestyle where murder was condoned and practiced as part of their religious system - that God could not - would not - forgive them. After trying repeatedly to get their attention, judgement was His only resource.
SO - what is God's "line in the sand?" I believe that it's the shedding of innocent blood. God cannot - will not - tolerate this great evil, and judgement WILL come on the nation that allows this practice to continue. We see and hear all around us the support for child sacrifice in abortion - politicians at the highest levels of government not just condone it, but encourage it, and many have even gone so far as to say that it's a "religious right!" Unless His Church wakes up - and "stands in the gap" for these innocents, God's judgement WILL come. We've crossed His "line in the sand" - and are so far beyond it now that one wonders if we can go back. I certainly hope that Christians are beginning to realize the need for action - for repentance - for standing up for what's right. If we start acting like the "salt of the earth and the light of the world," perhaps we can move our culture back across that line.