The doctrine of common grace teaches that God restrains mankind's sin and blesses the entire human race in a general manner.
Reformed scholar Louis Berkhof defines common grace in this way:
[Common grace] curbs the destructive power of sin, maintains in a measure the moral order of the universe, thus making an orderly life possible, distributes in varying degrees gifts and talents among men, promotes the development of science and art, and showers untold blessings upon the children of men.
For he makes his sun rise on the evil and on the good, and sends rain on the just and on the unjust.
This means that God has a general kindness towards all humans in that He restrains their sin so that they are not nearly as bad as they could be.