Background:
Ahaz, the son of Jotham, reigned as king of Judah from approximately 732 to 716 BC. His reign is noted for its significant departure from the religious practices established by his predecessors, as he embraced idolatry and foreign customs. The account of Ahaz altering the temple altar is found in 2 Kings 16:10-16 and 2 Chronicles 28. Ahaz's actions are often viewed as a turning point in the spiritual decline of Judah, as he sought alliances with foreign powers and adopted their religious practices.

Biblical Account:
The narrative in 2 Kings 16:10-16 describes how Ahaz, after visiting Damascus to meet with Tiglath-Pileser III, king of Assyria, was impressed by an altar he saw there. "When King Ahaz went to Damascus to meet Tiglath-Pileser king of Assyria, he saw the altar in Damascus and sent to Uriah the priest a model of the altar and a detailed design of its construction" (2 Kings 16:10). Ahaz instructed Uriah the priest to build an altar in Jerusalem based on this design.

Upon his return, Ahaz offered sacrifices on the new altar, which he placed in a prominent position in the temple, moving the original bronze altar to the north side. "King Ahaz commanded Uriah the priest, saying, 'On the great new altar offer the morning burnt offering, the evening grain offering, the king’s burnt offering and grain offering, and the burnt offering of all the people of the land, their grain offering, and their drink offerings. Sprinkle on it all the blood of the burnt offerings and sacrifices. The bronze altar will be for me to seek guidance'" (2 Kings 16:15).

Religious Implications:
Ahaz's actions represented a significant deviation from the worship practices prescribed in the Mosaic Law. The original altar, constructed according to divine specifications given to Moses, was central to the sacrificial system and the worship of Yahweh. By replacing it with a foreign design, Ahaz not only compromised the sanctity of the temple but also introduced elements of pagan worship into the heart of Judah's religious life.

This alteration of the temple altar is emblematic of Ahaz's broader religious apostasy. 2 Chronicles 28:2-4 details his engagement in idolatrous practices, including making molten images for the Baals and burning his children in the fire, following the abominations of the nations whom the LORD had driven out before the Israelites.

Political Context:
Ahaz's decision to alter the temple altar was closely tied to his political strategy. Facing threats from the northern kingdom of Israel and Aram, Ahaz sought the protection of Assyria, becoming a vassal to Tiglath-Pileser III. This alliance required Ahaz to adopt Assyrian customs and religious practices, further entrenching foreign influence in Judah.

Theological Reflection:
From a theological perspective, Ahaz's actions are seen as a violation of the first commandment, which prohibits the worship of other gods. His willingness to compromise the distinctiveness of Israel's worship for political gain reflects a lack of faith in God's covenant promises. The alteration of the temple altar serves as a cautionary tale about the dangers of syncretism and the erosion of religious identity in the face of external pressures.

Legacy:
Ahaz's reign is remembered as a period of spiritual decline, setting the stage for the eventual downfall of Judah. His son, Hezekiah, would later attempt to reverse these changes and restore proper worship, but the seeds of idolatry and compromise sown during Ahaz's reign had lasting consequences for the nation.