Question: "What was the significance of the altar King Ahaz built?"
Answer: Second Kings 16 describes the reign of King Ahaz in Judah. During his reign, he went to Damascus to meet Tiglath-pileser, king of Assyria (verse 10). While there Ahaz saw the altar the Assyrians used and sent a model of it to Uriah the priest in Jerusalem with orders for Uriah to construct a life-size, working replica.
Uriah did as the king commanded and had the altar built for the king’s return. Ahaz then commanded that the daily offerings of worship to the Lord take place on this new altar. Ahaz said he would decide what to do with the original altar of the Lord (verses 15–16).
Ahaz’s desecration of the temple continued: “And King Ahaz cut off the frames of the stands and removed the basin from them, and he took down the sea from off the bronze oxen that were under it and put it on a stone pedestal. And the covered way for the Sabbath that had been built inside the house and the outer entrance for the king he caused to go around the house of the LORD, because of the king of Assyria” (verses 17–18).
Other evils of Ahaz are summarized in 2 Chronicles 28:1–4, “And he did not do what was right in the eyes of the LORD, as his father David had done, but he walked in the ways of the kings of Israel. He even made metal images for the Baals, and he made offerings in the Valley of the Son of Hinnom and burned his sons as an offering, according to the abominations of the nations whom the LORD drove out before the people of Israel. And he sacrificed and made offerings on the high places and on the hills and under every green tree.”
This same chapter notes that, as a result of Ahaz’s wickedness, the Lord allowed Judah to be defeated by Syria and Israel. In one day, 120,000 men died, and 200,000 were taken as servants to Samaria. Instead of turning to the Lord, Ahaz requested help from Assyria, but they afflicted him instead (verse 20). In his distress Ahaz sacrificed to the gods of Damascus that had defeated him (verse 22).
In the end, Scripture records, “Ahaz gathered together the vessels of the house of God and cut in pieces the vessels of the house of God, and he shut up the doors of the house of the LORD, and he made himself altars in every corner of Jerusalem. In every city of Judah he made high places to make offerings to other gods, provoking to anger the LORD, the God of his fathers” (2 Chronicles 28:24–25). King Ahaz was so despised that, when he died, he was not buried in the tombs of the kings in Jerusalem (verse 27).