Upvote:2
Both in Biblical times and modern times, the two great dangers the Scripture warns against are idolatry (failing to recognize God as Creator and worthy of praise) and immorality (injustice against our fellow humans and disobedience to God) and the two are often linked. In Romans 1, we see that idolatry leads to immorality. Worshiping money is one example of idolatry that often leads to injustice.
The word heresy normally refers to false doctrine, whether that is a rejection of the Trinity or the deity of Jesus. While people on this site may disagree on what constitutes heresy, I think there would be widespread agreement that we are to avoid idolatry and immorality if we want to pursue devotion to Christ.