1)
Why will they be ashamed of Kemosh?
1.
Rashi: They trusted in it. Radak - it was their god.
2)
What will be the consequence of their shame?
1.
Malbim: They will see that idolatry has no reality, and one should not trust in it.
3)
What was in Beis Kel that Yisrael trusted in it?
1.
Rashi: A golden calf [of Yaravam].
4)
Why does it mention that also Yisrael trusted in idolatry?
1.
Radak: This teaches that they [were able to] harm Yisrael not due to their virtue, rather, due to the sin of Yisrael, who trusted in [the calf] in Beis Kel.