Gentiles … who show the work of the law written in their hearts, their conscience also bearing witness, and between themselves their thoughts accusing or else excusing them.
Romans 2:15.
Among the despised heathens there were individuals who complied with the demands of the law without knowing it. They showed that “the work of the law” was written in their hearts. They considered it right to revere the Creator-God and honour their parents. They knew it to be wrong to murder or steal. Their conscience was their moral power, the pointer that indicated whether they lived according to their natural moral sense.
The self-righteous Jews, who took offence at the apostle’s message, had to admit these albeit rare instances of the heathen not living in the darkness of idolatry and immorality held up before them. Such heathen people did not seek God of their own accord and are not counted among the “righteous” by nature. Nor are they justified by works (cf. Romans 3:9-12:20).
How God worked in the hearts of such heathens people, how He saved them, granting them spiritual life who sought to do God’s will is a mystery that the book of Job unveils to a degree.
Job was not of the nation of Israel, and he lived before the time of the law. Yet he avoided idolatry and immorality; indeed he was “blameless and upright, and one who feared God and shunned evil”. But he was not completely free from self-righteousness. In the sufferings he experienced he obtained a better acquaintance of himself and held firmly on to his Redeemer (cf. Job 1:1.5;19:25-27;42:6).