A presbyter from Augustine's monastery, Boniface, made an accusation of a sexual sin against a monk from the same monastery, Spes, who in turn accused Boniface of the same infringement. Augustine could not determine the truth, so he sent the two to the shrine of St Felix in Nola for a form of a divine judgement. Before that, he did not want to remove Boniface from the list of the clergy. Similar explanation was presented in the precedent Letter 77, also relating to the issue. Letter 77 was sent to two laymen of Hippo, whereas Letter 78 is addressed to "the clergy, the elders, and all the people of the Church of Hippo".
We can note also the content of the commendation letter which Augustine gave to Boniface, which – at his own demand – did not confirm his clerical privileges.