Rehoboam went to Shechem, [to be proclaimed] king. 1 Kings 12:1
As God had foretold to Solomon, the Israelites divided themselves into political camps. The Northern Kingdom held ten tribes and kept the name Israel. The Southern territory, belonging to the tribe of Judah (with remnants of the tribe of Benjamin) became a separate kingdom.
… Israel [the Northern Kingdom] went into rebellion against David’s house … all Israel … summoned [Jeroboam] to an assembly and made him king over all Israel. 1 Kings 12:19-20
There was constant warfare between Rehoboam and Jeroboam. 1 Kings 14:30
There was constant warfare between the Northern Kingdom of Israel and the Southern Kingdom of Judah.
Meanwhile, …
The prayer of the People of God [had flourished] in the shadow of God’s dwelling place, first the ark of the covenant and [now] the Temple. # 2578
So, up in the Northern Kingdom …
Jeroboam thought to himself: “… If now this people go up to offer sacrifices in the temple of the LORD in Jerusalem,
(as the Law commanded)
the hearts of this people will return to … Rehoboam, king of Judah, and they will kill me.” … [Jeroboam] made two calves of gold and said to the people: “You have been going up to Jerusalem long enough. Here is your God, O Israel, who brought you up from the land of Egypt.” And he put one in Bethel, the other in Dan. This led to sin, because the people frequented these calves in Bethel and in Dan. 1 Kings 12:26-30
For the People of God, the Temple was to be the place of their education in prayer: pilgrimages, feasts and sacrifices, … But ritualism often encouraged an excessively external worship. #2581
If our heart is far from God, the words of prayer are in vain. # 2562 see also 2570
Excessively external worship at the temple was bad enough. Jeroboam and his subjects in the Northern kingdom of Israel did not even pray to God. It was like going through the motions of drinking, but drinking from an empty glass. They could go through all the right motions, but it would never satisfy their thirst for the one, true, living God.
So Ahijah, [the prophet] … said, “… ‘This is what the LORD, the God of Israel, says: [Jeroboam has] done worse than all who preceded [him] … made … strange gods and molten images to provoke me; …Therefore, 1 Kings 14:6-9
[The Lord] will give up Israel because of the sins Jeroboam has committed and caused Israel to commit.” 1 Kings 14:16