The document discusses the sin of partiality, which is showing favoritism or prejudice towards others based on factors like wealth, race, or social status. It explains that partiality is wrong for several reasons: it contradicts the teachings of Jesus by treating people unequally; it involves unjustly judging and despising others; and it breaks the royal law of loving your neighbor. The document uses examples from the New Testament to illustrate how early Christians struggled with partiality and why God condemns this sin.