classical logic is sinful. we derive meaning and knowledge from what god gives us - first-person experience, and divine revelation is a kind of that. to claim that we can know beyond that is blasphemous. that's like attributing omniscience to oneself, claiming to be like god. greed, laziness, desire for easy ways, like proof by contradiction, contraposition, consequentia mirabilis, and sequent calculus, are tempting paths to sin. georg cantor communicated with satan disguised as God. model and set theories are evil mockeries of math.
if you are a Christian mathematician, you should only use constructive logics. usage of non-constructive logics is a path to hell.