What does the Bible say about respect of persons?

Proverbs 28:21 explicitly tells us that to have respect of persons is not good; favoritism, particularly for personal gain, leads to injustice and sin. This concept is reiterated throughout the Scriptures, including in Proverbs 18:5, where favoritism is condemned as it can cause one to act against righteousness. God Himself is described as one who does not show favoritism (Acts 10:34), emphasizing the importance of fairness and justice in judgment, a principle that applies equally to personal relationships and the preaching of the gospel.