The rich young ruler of Luke 18:18-25 (also Matthew 19:16-26 and Mark 10:17-27) was told by Jesus that he should give all his wealth to the poor. And yet this is not a condemnation of markets or wealth inequality. I suggest that this was to point out that Jesus was putting a finger on the very thing that this man held in higher regard than God: his material wealth. Those who have wealth are strongly tempted to idolize it and reject God in favor of those temporary comforts wealth allows. But wealth is not evil. Ethical means of gaining wealth through markets aren’t evil either.
The book of Amos played a large part in the professor’s argument. Remember that Amos was a prophet and was speaking God’s words to the people, and especially a group of powerful wealthy people in Israel. He used harsh words for the fattened rich who relax in one of their multiple houses and “crush the needy” while asking for another drink. (Amos 3:15-4:1)
Clearly, the behavior of these people toward the poor was not the only criticism. God also rebuked them for their murderous warfare (1:13), hypocritical worship (5:21), idolatry (5:26), repression of God’s messengers (2:12, 7:16), and arrogance (6:13). But the professor’s concern was the inequality of wealth and the alleged use of markets to violate the rights of the poor. It was a concern with distributive justice. Watch out for modifiers like “distributive” or “social” before the word “justice.” They’re code for “equal outcomes are the standard of right and wrong.”
God does not rebuke these people because they used markets, or because they had greater wealth than others, but because they murdered, stole, and cheated. Look at the criticism of the Ammonites in Amos 1:13. They had committed horrific acts of violence to gain land. Look at Amos 5:11, 12. The accusation against these wealthy people is that they took taxes and had corrupt courts (city gates were the traditional location of courts).
This, ironically, is a governmental activity. It is not a condemnation of capitalism. Look at Amos 8:5, 6. How are these people who “swallow up the needy and make the poor of the land fail” obtaining wealth? They were falsifying measurements (it may help to know that an ephah is a measure of volume—like a bushel—and a shekel is a monetary unit). In free markets, cheating and other contract-breaking occurs, but these are not bound up in the nature of markets. The presence of such behavior does not condemn markets as a system any more than the existence of child abuse condemns families as an institution.
I do not believe a Christian who attempts to follow the Bible’s ethical requirements (as an aside, I don’t know what other kind of Christian one could be) will find a genuine moral dilemma in supporting a free market order.