"Do not be arrogant but be afraid. For if God did not spare the natural branches, He will not spare you either. Therefore, consider God’s kindness and severity: severity toward those who have fallen but God’s kindness toward you —
IF you remain in His kindness.
Otherwise you too will be cut off. Romans 11:20-22
For God did not spare even the angels who sinned. He threw them into hell, in gloomy pits of darkness, where they are being held until the day of judgment.
God didn't spare the ancient world either. He brought the flood on the world of ungodly people, but he protected Noah and seven other people. Noah was his messenger who told people about the kind of life that has - God's approval.
  2 Peter 2:4,5