Definition and Characteristics:
Righteous men, according to the Bible, are those who live in accordance with God's laws and commandments, exhibiting moral integrity and uprightness. The concept of righteousness is deeply rooted in the character of God, and righteous men are those who strive to reflect His holiness in their lives. The Hebrew word for righteousness, "tsedeq," and the Greek word "dikaios," both convey the idea of justice, virtue, and moral rectitude.

Biblical Examples:

1. Noah: Noah is one of the earliest examples of a righteous man in the Bible. Genesis 6:9 describes him as "a righteous man, blameless among the people of his time, and he walked faithfully with God." Noah's righteousness is demonstrated by his obedience to God's command to build the ark, saving his family and the animal kingdom from the flood.

2. Abraham: Known as the father of faith, Abraham's righteousness is highlighted in Genesis 15:6: "Abram believed the LORD, and it was credited to him as righteousness." His faith and obedience to God's call to leave his homeland and his willingness to sacrifice Isaac are key aspects of his righteous character.

3. Job: The Book of Job presents Job as a paragon of righteousness. Job 1:1 states, "There was a man in the land of Uz whose name was Job. And this man was blameless and upright, fearing God and shunning evil." Despite severe trials, Job's steadfast faith and integrity exemplify the endurance of a righteous man.

4. David: King David, despite his moral failings, is often described as a man after God's own heart (1 Samuel 13:14). His psalms frequently express a deep longing for righteousness and a desire to live in accordance with God's will. Psalm 37:25-26 reflects his understanding of righteousness: "I have been young and now am old, yet never have I seen the righteous abandoned or their children begging for bread. They are ever generous and quick to lend, and their children are a blessing."

5. Daniel: Daniel is another exemplary figure of righteousness. In Daniel 6:4, it is noted that "the administrators and satraps tried to find grounds for charges against Daniel in his conduct of government affairs, but they were unable to do so. They could find no corruption in him, because he was trustworthy and neither corrupt nor negligent." His unwavering commitment to prayer and adherence to God's laws, even in the face of persecution, highlight his righteous character.

Teachings on Righteousness:

1. The Path of the Righteous: Proverbs 4:18 states, "The path of the righteous is like the first gleam of dawn, shining brighter and brighter until midday." This verse illustrates the progressive nature of righteousness, suggesting that a righteous life grows in clarity and purpose.

2. Righteousness and Faith: The New Testament emphasizes the connection between faith and righteousness. Romans 1:17 declares, "For the gospel reveals the righteousness of God that comes by faith from start to finish, just as it is written: 'The righteous will live by faith.'" This underscores the belief that righteousness is not achieved by works alone but through faith in God.

3. The Reward of the Righteous: Scripture often speaks of the blessings and rewards for those who live righteously. Psalm 34:15-17 assures, "The eyes of the LORD are on the righteous, and His ears are inclined to their cry. But the face of the LORD is against those who do evil, to blot out their memory from the earth. The righteous cry out, and the LORD hears; He delivers them from all their troubles."

4. Righteousness and Justice: Righteousness is closely linked with justice in the Bible. Isaiah 56:1 commands, "Thus says the LORD: 'Preserve justice and do righteousness, for My salvation is close at hand and My righteousness will soon be revealed.'" This highlights the expectation that righteous men will also be advocates for justice in their communities.

5. The Righteousness of Christ: The ultimate example of righteousness is found in Jesus Christ. 1 Peter 3:18 states, "For Christ also suffered for sins once for all, the righteous for the unrighteous, to bring you to God." Through His life, death, and resurrection, Christ embodies perfect righteousness and offers it to believers through faith.

Conclusion:
Righteous men in the Bible are those who live in alignment with God's will, demonstrating faith, integrity, and a commitment to justice. Their lives serve as examples and encouragement for believers to pursue righteousness through faith in God and adherence to His commandments.