Deuteronomy 6:15

( for the Lord, thy God, is a jealous God among you, Exodus 20:5) lest the anger of the Lord, thy God, be kindled against thee, like a fire that grows beyond control, and destroy thee from off the face of the earth. That was the punishment which He threatened in the case of gross idolatry. These admonitions apply also to us. It is our duty not only to ponder the will of the Lord in our hearts, but also to confess it with our mouth and to practice it in our life.