The Israelites of the northern kingdom were very zealous in their pursuit of false worship. This is evident from the words directed to them through the prophet Amos: “‘Come, you people, to Bethel and commit transgression. At Gilgal be frequent in committing transgression, and bring your sacrifices in the morning; on the third day, your tenth parts.

Amos 4:4, 5.

Bethel was a center of false worship. It was there that Jeroboam, the first king of the northern kingdom, set up a golden calf. (1 Ki. 12:28-30) Gilgal, too, must have become a site for apostate worship. Therefore, Israel’s offering sacrifices at Bethel and Gilgal was really a transgression against Jehovah.