People's motives in serving Christ vary from pure to sinful. However, other men’s motives should not rob us of the joy of Jesus Christ being preached.
People in the world are generally quite self-centered. Even saved people are often lovers of their own selves instead of preferring one another.
Most men place their greatest emphases upon the here and now. Paul knew that life truly began at the moment man leaves his body to be present with the Lord.