When Saint Francis was 19 years old, he joined the military. During the military expedition against Perugia, he was captured and imprisoned for a year. Some people say that during that year, Saint Francis was converted to Christianity, but when he went back to his home, he reverted to his carefree habits.
Saint Francis fell ill a year later and rejoined the army in 1204. Then, he had a vision. The vision told him to return back to Assisi and to learn about God. Thus, Saint Francis went back to Assisi and stayed there for a long time in meditation.
There, he asked God for wisdom, he cared for the sick, and also pilgrimaged to Rome to spread the gospel. His family was unhappy at this, so he renounced his father and lived as a beggar in Assisi.
Saint Francis then heard a life changing sermon concerning repentance. Saint Francis continued his spreading of the Gospel with renewed energy. Because of this, Saint Francis had many followers who also followed him to preach repentance to others.
Saint Francis loved nature and believed that everything ought to praise God, even the ants. Then, in 1226 Saint Francis claimed that he received wounds similar to Christ, and also became blind. That year, when he was just about to die, he said his testimony and died singing Psalms 142.
Saint Francis was made saint after his death, and his example shows that we may live happily on earth even without wealth.