Replacing the Feast of Tabernacles, Israel’s main ceremonial feast in the seventh month, with a festival in Bethel broke the law (Deuteronomy 16:13–15). Holding this imitation festival one month later in the eighth month might have matched the end of the Canaanite agricultural year. Jeroboam’s false religious practices led to Israel’s downfall (2 Kings 17:22).
Jeroboam’s offering of sacrifices on the altar at Bethel set a poor example in spiritual leadership.