SPIRITUAL ADULTERY
Spiritual adultery is unfaithfulness to God. It is having an undue fondness for the things of the world. Spiritually adultery is analogous to the unfaithfulness of one’s spouse: “‘But like a woman faithless to her lover, even so have you been faithless to me, O house of Israel,’ says the LORD” (Jeremiah 3:20; see also Isaiah 1:21; 57:8; Ezekiel 16:30).
This is a good article on the issue of spiritual adultery.