Jehonadab, son of Recab, was quite a man. He was an upstanding man of iron principle who taught his children and grandchildren the precepts of righteousness. His biblical career started when he joined Jehu in destroying the prophets of Baal (2 Kings 10:15-17). Jehu saw in Jehonadab a man who would not compromise with Jezebel and her wicked prophets, but would follow through in delivering judgment against them.
Jehonadab commanded his children and grandchildren to live by certain standards and principles, and these principles were still being upheld centuries later during Jeremiah's day. In Jeremiah 35:5-6, Jeremiah offered Jehonadab's family huge bowls full of wine, which they refused. They strictly maintained the principles of purity they had received from their ancestor many years before. Jeremiah used the family of Jehonadab as a perfect example of a family who consistently put principles ahead of personal choice.
It's easy to change your convictions because they don't feel good. King Jehoiakim just took a knife and cut out the parts of the Bible he didn't like (Jeremiah 36:23)! Don't change your Bible to fit your lifestyle. Change your lifestyle to fit your Bible. In the end, you'll be glad you did!