42. This verse refutes the wrong criterion by which the disbelievers of Makkah (and all other disobedient people of the world) judged whether one was or was not a favorite of God. They judged a man’s worth by his wealth and worldly prosperity and not by his faith and righteous conduct. They thought that the one who was enjoying all the good things of life was a favorite of God, even if he had erroneous beliefs and did wicked deeds. On the other hand, they considered the one who was poor and indigent to be under the wrath of God, even though he was righteous. That is why in their judgment the chiefs of the Quraish were far superior to the followers of the Prophet (peace be upon him). They would say, "You can see for yourselves that God is with the chiefs of the Quraish.
In this verse, Allah has warned them that they are absolutely wrong in drawing such a conclusion from the worldly conditions of the people. Allah gives His provision to the people abundantly or sparingly for reasons different from those which they presumed and richness or poverty is no criterion by which to judge the worth of people. The real criterion of judging the worth of people is their beliefs and deeds. The one, who has righteous beliefs and does good deeds, shall be higher in rank than the one who has wrong beliefs and does evil deeds. Thus the real criterion is the quality of his deeds and not the possession or the lack of wealth.