The Franciscan — John L. Cowart

Ramon kills the man who murdered his fiancée and flees to the New World disguised as a Franciscan Friar. In Mexico, he lives a life of debauchery, but when his girlfriend attempts suicide, and he repents and vows to take his religion seriously and become a holy monk. His superiors send him to New Mexico to carry Catholicism to the Indians. Once there, he discovers that the Spanish soldiers are abusing the Indians and the pastor at the Pecos Pueblo is sexually abusing the boys.