That dude does need to lighten up. Who cares that ancient customs sometimes mirror or make their way thousands of years down the road. Those people were not much different from us and we are all on the same rock hurtling through space. Its safe to say traditions will mix, religions will overlap, really good songs will sound like other songs, and even things that happened 1000's of yrs ago are still remembered today. Since when do we deny that? Hell know we watch history and discovery channel because we love **** like that.
Who cares if being a Christian makes you a better person then you should do it. If it isn't for you then find something else that makes you less selfish. If thats just your own moral code because you kick ass, then have at it.