LITTLE FLOWERS OF SAINT FRANCIS OF ASSISI, Chapter 26
HOW ST FRANCIS CONVERTED CERTAIN ROBBERS AND ASSASSINS, WHO BECAME FRIARS; AND OF A WONDERFUL VISION WHICH APPEARED TO ONE OF THEM WHO WAS A MOST HOLY BROTHER
The first half of this chapter reminds me of the saying, "You catch more flies with honey than you do with vinegar." It provides an excellent contrast between effective witnessing and ineffective, and the difference is in having or not having God's love for all his creatures in our hearts.
Three robbers are converted and two die soon after conversion. But the third robber eventually has a vision in which he is made to bare much suffering, and in which he gets to Heaven and Saint Francis says he'll come and bring him back in seven days.
There are a lot of things to think about here, and not just in working out an allegorical interpretation.