The leader of Catholics all over the world made the comments at his general audience on Wednesday.
He said clergy who use their position for personal gain, rather than to help those in need, are not working in the spirit of Jesus.
He said Jesus took upon himself the sufferings of others and criticised leaders who did not help others.
"Jesus was not a prince," said the pope.
"It is awful for the Church when pastors become princes, far from the people, far from the poorest people. That is not the spirit of Jesus."
Before speaking, Pope Francis travelled around St Peter's Square in the Popemobile, greeting pilgrims.
Francis concluded his general audience, saying Jesus was "a pastor who was among the people, among the poor."
Pope Francis holds a weekly general audience where he addresses different issues in front of thousands of believers.