Is God jealous in the matters of his worship? Yes

From Matthew Henry’s A Scripture Catechism in the Method of the Assembly’s 

Matthew henryQ. 52. What are the reasons annexed to the second commandment?
A. The reasons annexed to the second commandment, are God’s sovereignty over us, his property in us, and the zeal he has to his own worship.

1. Is there good reason why we should take heed of idolatry? Yes: Turn ye not to idols, neither make to yourselves molten gods, I am the Lord your God, Lev. 19:4. Has God a sovereignty over us? Yes: for he is a great God, and a great King above all gods, Ps. 95:3. Ought we therefore to worship him, as he has appointed us? Yes: O come let us worship, and bow down, and kneel before the Lord our Maker, Ps. 95:6. And not to worship idols? Yes: for they can do neither good nor evil, Isa. 41:23.

2. Has God a property in us? Yes: for we are the people of his pasture, Ps. 95:7. Ought we therefore to worship him? Yes: He is thy Lord, and worship thou him, Ps. 45:11. And not to worship other gods? Yes: for hath a nation changed their gods? Jer. 2:11.

3. Is God jealous in the matters of his worship? Yes: The Lord, whose name is Jealous, is a jealous God, Exod. 34:14. Is he much displeased with those who corrupt it? Yes: They provoked the Lord God of Israel to anger with their vanities, 1 Kings 16:13. Do those who do so hate him? Yes: Idolaters are haters of God, Rom. 1:25, 30. Will he visit their iniquity? Yes: In the day m when I visit, I will visit their sin upon them, Exod. 32:34. Will he visit it upon the children? Yes: Our fathers sinned, and are not, and we have borne their iniquities, Lam. 5:7. And is it just with him to do so? Yes: for they are the children of whoredoms, Hos. 2:4. But will he visit it for ever? No: but to the third and fourth generation, Exod. 34:7.

4. Will those who love God keep his commandments? Yes: If ye keep my commandments, ye shall abide in my love, John 15:10. Will he show mercy to such? Yes: for he hath said, I love them that love me, Prov. 8:17. Will he show mercy to thousands of such ? Yes: for the mercy of the Lord is from everlasting to everlasting, Ps. 103:17.