Westminster Shorter Catechism

Q48

What are we specially taught by these words before me in the first commandment?

These words before me in the first commandment teach us, that God, who seeth all things, taketh notice of, and is much displeased with, the sin of having any other God125.
Duty
Ch. XXI Of Religious Worship, and the Sabbath Day

Scripture Proofs

125
Deuteronomy 30:17-18Psalm 44:20-21Ezekiel 8:12