Among other things, Paul had been beaten, stoned and imprisoned numerous times. Still, he kept preaching about Christ. Paul did not allow things of this world to hinder the shinning of his light to the lost. Christ instructed the people he taught to be examples to those in the world. Christ has commanded us to show our faith to others, not hide it inside ourselves.
Christians can show their lights in many ways.
Our message to the world is Christ and his plan for our salvation. Let us not be like a broken sign with the message inside.