So the Lord said, “If I find in Sodom fifty righteous within the city, then I will spare all the place for their sakes.” Gen 18:26

The population of cities of Sodom and Gomorrah is an unknown. Sodom was a bustling city of commerce and had some wealth to it. It had a king and a ruling party and probably some aristocrats, middle class, business owners, and the poor all living within the city.

God decided to judge the region because of the sin committed by the people living there – pride, fullness of food, and abundance of idleness; neither did she strengthen the hand of the poor and needy. And they were haughty and committed abomination. Ezek 16:49-50
Abraham bargained for their lives starting with sparing everyone for the sake of fifty righteous people within the city. He made it all the way to ten.
The region saw the judgment of God come upon it since not even ten righteous people lived in Sodom.

This scripture shows two things about God.
First, it shows the severity of sin and how He deals with it. Ezekiel 18:4 says the soul who sins shall die. Paul says in Rom 6:23 the wages of sin is death.
God cannot allow sin to continue on and on. Some find this disturbing that He allows it to continue now.
This reveals the second thing about God – His mercy and grace.

While He allows sin to affect your life, He also gives you a way to combat it.
The wages of sin is death, but the gift of God is eternal life in Christ Jesus our Lord. Rom 6:23
If He did not care, why would He bother?
God eventually deals with sin at a future date.
And as it was in the days of Abraham, He looks for righteousness in the hearts and lives of people – to spare them from judgment.
The righteousness He looks for is through that of Jesus Christ living in the hearts and lives of people.
Only through His righteousness are you spared.