What are your unprovable moral axioms?
Well, Christian moral axioms are numerous (as any complete morality is not simple). But start by considering the 10 commandments. Go on to those provided by Jesus - that we should love all (even our worst enemies), that to judge another is bad (though not to judge a person's actions), that to forgive any who truly repent is good, that to reserve sexuality for marriage (and to consider marriage a true life-long, for better or worse commitment) is good, that to seek humility and shun pride is good, that to turn the other cheek when struck is good, etc. etc. etc. In short, that to shun sin as defined by Christ and the Law & Prophets who preceded him is inherently good. And that to follow the example of Christ is inherently good.