The comedy as a genre sticks to literary conventions. It starts from adverse situations to a happy or favorable ending. The fact Dante's Divine Comedy begins in hell makes the text secular, or profane. The church in those times was punitive with that type of texts. As a conjecture it can be said that the writer chose to write his views on Christianity in an indirect manner out of fear for negative consequences against him and a way of protection.
Most likely because it was a comedy and he was joking about but if he talked about maybe(these are just guesses) that he is a Christian and didn't want to say anything mean or hurtful cause in the end then he would only be hurting himself or that he didn't want to be clobbered by the Christian because Christians have killed because of there religion just look at the crusades on the soldiers Way they saw Jews and assassinated them because they believed all the Jews were at fault for Jesus's death.
