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1 And Jehoshaphat the king of Judah returned to his house in peace to Jerusalem. 2 And Jehu the son of Hanani the seer went out to meet him, and said to king Jehoshaphat, Shouldest thou help the ungodly, and love them that hate the LORD? therefore is wrath upon thee from before the LORD. 3 Nevertheless there are good things found in thee, in that thou hast taken away the groves out of the land, and hast prepared thine heart to seek God. 4 And Jehoshaphat dwelt at Jerusalem: and he went out again through the people from Beer-sheba to mount Ephraim, and brought them back unto the LORD God of their fathers. 5 And he set judges in the land throughout all the fenced cities of Judah, city by city, 6 And said to the judges, Take heed what ye do: for ye judge not for man, but for the LORD, who is with you in the judgment. 7 Wherefore now let the fear of the LORD be upon you; take heed and do it: for there is no iniquity with the LORD our God, nor respect of persons, nor taking of gifts. 8 Moreover in Jerusalem did Jehoshaphat set of the Levites, and of the priests, and of the chief of the fathers of Israel, for the judgment of the LORD, and for controversies, when they returned to Jerusalem. 9 And he charged them, saying, Thus shall ye do in the fear of the LORD, faithfully, and with a perfect heart. 10 And what cause soever shall come to you of your brethren that dwell in their cities, between blood and blood, between law and commandment, statutes and judgments, ye shall even warn them that they trespass not against the LORD, and so wrath come upon you, and upon your brethren: this do, and ye shall not trespass. 11 And, behold, Amariah the chief priest is over you in all matters of the LORD; and Zebadiah the son of Ishmael, the ruler of the house of Judah, for all the king's matters: also the Levites shall be officers before you. Deal courageously, and the LORD shall be with the good.
[AD 379] Basil of Caesarea on 2 Chronicles 19:3
If you see your neighbor committing sin, take care not to dwell exclusively on his sin, but think of the many things he has done and continues to do rightly. Many times, by examining the whole and not taking the part only into account, you will find that he is better than you. God does not examine humans according to the part, for he says, “I come to gather together their works and thoughts.” Furthermore, when he rebuked Josaphat for a sin committed in an unguarded moment, he mentioned also the good he had done, saying, “But good works are found in you.”

[AD 430] Augustine of Hippo on 2 Chronicles 19:7
Do not doubt that this duty of ours is a part of religion because God, “with whom there is no iniquity,” whose power is supreme, who not only sees what each one is but also foresees what he will be, who alone cannot err in his judgment because he cannot be deceived in his knowledge, nevertheless acts as the Gospel expresses it, “He makes his sun to rise on the good and bad, and rains on the just and unjust.”