it is detestable to the LORD your God: Pagan worship denies God's uniqueness and rejects his demand for exclusive worship (5:7–9). The terrible and disgusting ceremonies often linked to pagan worship opposed God's holy nature. But Israel risked adopting similar beliefs and practices (12:31; 13:12–17).
An Israelite who recognized or worshiped false gods committed treason against the Lord. In other words, that person was unfaithful to God as king. The only solution was the complete destruction of these detestable objects.