We should not confuse resurrection and ascension with the pagan idea of divine apotheosis. The Romans made Romulus a "god" because he founded Rome. Christians believe that the City of God is divine because it was founded by Christ:
But though Christ is the founder of the heavenly and eternal city, yet it did not believe Him to be God because it was founded by Him, but rather it is founded by Him, in virtue of its belief. Rome, after it had been built and dedicated, worshipped its founder in a temple as a god; but this Jerusalem laid Christ, its God, as its foundation, that the building and dedication might proceed. The former city loved its founder, and therefore believed him to be a god; the latter believed Christ to be God, and therefore loved Him.This, in turn, leads to a different kind of city and a different kind of citizen body:
The city of Christ, which, although as yet a stranger upon earth, had countless hosts of citizens, did not make war upon its godless persecutors for the sake of temporal security, but preferred to win eternal salvation by abstaining from war. They were bound, impriRomsoned, beaten, tortured, burned, torn in pieces, massacred, and yet they multiplied. It was not given to them to fight for their eternal salvation except by despising their temporal salvation for their Saviour’s sake.Our City is built on faith, and whenever faith is rejected we fall away from the City. This is in contrast to the city of man, which is built on works, honor, etc.
If Cicero rejects Romulus as a "god" as a result of his (Cicero's) more enlightened era, how much more enlightened must Augustine's time be? And yet we find that Jesus is not only not rejected, but increasingly believed in as a God. This is because He is truly Divine, not just the result of a mythical human elevation.