"Adultery" is man's betrayal of the Truth of God's Will that he has learned and his turning to false teachings, ideologies, false beliefs, his fornication with "harlot" religions.

"Adultery" is unfaithfulness to true spiritual principles, changing a true worldview to a false one, betrayal of the righteousness achieved by following God's Commandments, violation of spiritual, moral fidelity, betrayal of the common cause of fulfillment, of evangelizing the Will of God.  

"Adulterer" is a person who, by rejecting, violating, distorting God's Commandments, betrays his love for God, changing it to selfish love for himself and for his various political, religious and other idols.