The most significant teaching of Christianity is that 'the meek shall inherit the earth.'
(Matthew 5:5.) This revolutionary idea destroyed the pagan concept of power politics. Before Jesus, the king was God. After Jesus, political struggles could no longer for purely earthly power. The rulers had to claim virtue to rule, as well as might. No longer could they say, as the Athenians had to the Lesbians,
that 'we are not in a court of justice, but in a political assembly.'
Moreover, since Christianity preached the primacy of the individual, every human being could be seen as a potential citizen of the Kingdom of Heaven. If we are not to fear those who can destroy the body, (Matthew 10:28,) then the pursuit of virtue allows us to bravely face death.