Romans 1:14

‘I am debtor both to Greeks and to Barbarians, both to the wise and to the foolish.'

Indeed he feels under a great burden of debt to all men. He has received such a wonderful revelation and commission from God that he recognises that it has put him under an obligation to share it with others. It is a debt owed to all, whether sophisticated or unsophisticated, wise or less wise. None are exempt. And it is a debt owed by all who receive salvation to those who have not yet received it. Having been saved we come under an obligation to bring others to Christ.

When he speaks of the Greeks he is not simply speaking of people who came from Greece. Through the conquests of Alexander the Great, Greek influence and Greek culture had permeated the known world, and especially the great cities. Greek was spoken everywhere. And when Alexander's empire broke up the Greek culture and language remained. It was something men treasured and were proud of, to such an extent that they looked down on people who could only say, ‘bar-bar-bar' (Barbarians), which was what the non-Greek languages sounded like to them. So Paul is here speaking of both the sophisticated and educated of ‘Greek' culture, and the unsophisticated Barbarians.

There was also a class of people within the empire who saw themselves as ‘wise. They enjoyed the works and teaching of the philosophers, and looked down on those who neither read them nor understood them, seeing them as ‘foolish' (compare Acts 17:21). In their own way they were as separatist as the Pharisees, although for different reasons. But Paul wanted to stress that the foolish had as much right to the Good News as the wise, and in 1 Corinthians 1-2 he makes clear that it tended in fact to be the foolish who responded to the Good News (although not exclusively) for the wise were too self-satisfied with their own supposed wisdom.