This is a common theme in the Bible letter written by James, Jesus’ half-brother (excerpts from chapters 3 and 5):

My brothers and sisters, believers in our glorious Lord Jesus Christ must not show favoritism. Suppose a man comes into your meeting wearing a gold ring and fine clothes, and a poor man in filthy old clothes also comes in. If you show special attention to the man wearing fine clothes and say, “Here’s a good seat for you,” but say to the poor man, “You stand there” or “Sit on the floor by my feet,” have you not discriminated among yourselves and become judges with evil thoughts? 

Listen, my dear brothers and sisters: Has not God chosen those who are poor in the eyes of the world to be rich in faith and to inherit the kingdom he promised those who love him? But you have dishonored the poor. Is it not the rich who are exploiting you?

 Now listen, you rich people, weep and wail because of the misery that is coming on you. Your wealth has rotted, and moths have eaten your clothes. Your gold and silver are corroded. Their corrosion will testify against you and eat your flesh like fire. You have hoarded wealth in the last days. Look! The wages you failed to pay the workers who mowed your fields are crying out against you. The cries of the harvesters have reached the ears of the Lord Almighty. You have lived on earth in luxury and self-indulgence. You have fattened yourselves in the day of slaughter. You have condemned and murdered the innocent one, who was not opposing you.