IV. He shows them what a bad influence their sins had had upon others. The sins of God's professing people harden and encourage those about them in their evil ways, especially when they appear forward and ringleaders in sin (v. 33): Why trimmest thou thy way to seek love? There is an allusion here to the practice of lewd women who strive to recommend themselves by their ogling looks and gay dress, as Jezebel, who painted her face and tired her head. Thus had they courted their neighbours into sinful confederacies with them and communion in their idolatries, and had taught the wicked ones their ways, their ways of mixing God's institutions with their idolatrous customs and usages, which was a great profanation of that which was sacred and made the ways of their idolatry worse than that of others. Those have a great deal to answer for who, by their fellowship with the unfruitful works of darkness, make wicked ones more wicked than otherwise they would be.