Actually two millenium dude, we are in the third.
However your point addresses the unchanging nature of Islam.
The west developed because it shod State run by Religion. But Islam has changed too. Despite being told not to imitate the Kuffar, Muslim nations have
had to do this. A Islamic scholor from the 14th Century wrote, "Damm these infernal frankish devices that I must wear to be able to see", the Ottomans reformed their army on western lines even down to the uniforms and bands. Now I can understand the tactic's and equipment being changed for modern western design....but why the uniforms? Why copy something like tunics and braiding when traditional Turkish uniforms were just as practical? Moving on to more modern times, Muslim music is westernised, the ummah have adopted TV when it is something that is strongly arguable against in islamic law, the internet allows males to speak to females with anonyminity yet thats adopted too..Even in the middle east, the professional classes wear western suits rather than Arabic dress, beards are shaved off, the list is totally endless.
Muslims see this change as Shirk, there is strong resentment of it and in recent years the backlash is leading to more and more Muslims who were progressing along western lines to start wearing Hijab around western citys, overtly praying in public and getting back to core values. They see imitation of the Kuffar and hate it, and yet resent it as they can see the benifits of human progress. How this sits with Islamic scholars is the reason for much of the problems we see today.
If the west was to get back to core values we would regress the same way.