Jeremiah intercedes with God on behalf of his people in Judah. The coming destruction of Jerusalem was more than he could bear and he seeks to find an escape for the city. God seems to give him a chance to save the nation. Jeremiah 5:1 
says, “Run to and fro through the streets of Jerusalem, look and take note! Search her squares to see if you can find a man, one who does justice and seeks truth, that I may pardon her.” You only have to find one righteous man, Jeremiah! That’s all! Just one. Ryken comments, “God gave Jeremiah a chance to save his civilization. All he needed to find was one righteous man. Just one. Not 100, or fifty, or ten, or even two. Jeremiah was not looking for a few good men; he was looking for only one. The challenge was to find a plain-dealer, just one citizen who could be trusted. For the sake of one person of real integrity, God would forgive the sins of the entire city.”[1]
The verse gives no limitations. “Look everywhere in the city, Jeremiah,” God says. “Search every nook and cranny of the city.” Mackay adds, “The picture is not one of haphazard or aimless motion, but rather of thorough scrutiny of Jerusalem’s streets, the narrow alleys that lay outside the houses of ordinary folk, and of her squares, found at the intersection of the streets or else the open spaces within the city walls, generally near the gates, where people conducted civic and commercial business. The focus is particularly on the public conduct of Jerusalem.”[2]God is looking for a reason to spare the city. But we know that Jeremiah can’t find one!
Wasn’t Jeremiah a righteous man? Couldn’t God have spared the city for his sake? I think this is where Psalm 14:2-3 come in. It says, “The LORD looks down from heaven on the children of man, to see if there are any who understand, who seek after God. They have all turned aside; together they have become corrupt; there is none who does good, not even one.” Paul repeats this truth in Romans 3:23, “For all have sinned and fall short of the glory of God.” This is not only the condition of the citizens of Judah, it’s the condition of the entire human race. Thankfully as Ryken says, “Through the grace, the life, the righteous act, and the obedience of the one man, justifying grace comes to many. Look as long as you like, there is no other answer to Jeremiah’s quest. God sent his own Son, Jesus Christ, the Righteous One, to save the city. A good man is hard to find, but not impossible.”[3]
[1] Philip Graham Ryken, Jeremiah and Lamentations: From Sorrow to Hope, Preaching the Word (Wheaton, IL: Crossway Books, 2001), 84–85.
[2] John L. Mackay, Jeremiah: An Introduction and Commentary: Chapters 1–20, vol. 1, Mentor Commentaries (Fearn, Ross-shire, Scotland: Mentor, 2004), 239.
[3] Philip Graham Ryken, Jeremiah and Lamentations: From Sorrow to Hope, Preaching the Word (Wheaton, IL: Crossway Books, 2001), 94.