“In this passage we find further instructions given through Moses for the purification of God's worship in the promised land…

The first thing the people were to do when they inherited the land was to demolish every remnant of idolatry that they found there and to destroy every place in which the abominable idolatry of the dispossessed heathen had been practiced. This was to be done, not only for the sake of purging the land of that which had provoked God’s anger, but also to remove a stumbling block from before His own people. Therefore He adds. ‘You shall not worship the Lord your God with such things!’ which would hardly have been necessary to add if the people were not prone to corrupt God's pure worship with the importing of pagan rites and practices.

Moses well understood the inclination of the human heart to corrupt the worship of God by adding to it the elements of idolatry. It would only be a matter of time before the people began to import the practices of the pagan nations around them, into their worship. It was all done, of course, in the name of ‘enhancing’ the worship of Jehovah and ‘improving’ the ceremonies that He had given to them by divine command. In God's eyes, however. it was spiritual adultery and contemptible idolatry.” (Comin 51-52)