I wouldn’t be a Christian

[The Grand Nudger]

Not only was this not a particularly christian belief, it's not a christian belief (christians believe in forever, and an eternal god with no beginning)...but it was a belief of many of the pagans that christian civilization eradicated.  If you google linear time, you will be flooded with names of pre christian philosophers, and even a cursory glance of european mythology will be bursting with beginnings of time and ends of days left right and center.

Christians believe that God has existed forever, but that human history has a beginning and an end and enacts a drama. What other culture should I look at for the origin of this?

That is a globally common belief.  You can look anywhere you like.

As for your claim that Christianity has no Hebrew elements, I think this is a field you could look in to some more. Greek culture, for example, has no notion of a savior figure, or the need for people to receive salvation. Of course Jews think that Christians have misunderstood and deformed the proper view of a savior, but that doesn't change its origin. 

The hellenistic culture that christianity arose out of was roman, not greek.... they too had been hellenized (just as we have, with christianity as the vehicle), jesus was one of many contemporary savior figures in -their- pre christian society.  It was a trend, a thing, at the time.

There is a great deal of Old Testament teaching and symbolism present in the New Testament. Again, this was deformed from a Jewish perspective, but is nonetheless Jewish in origin. 

That's the claim (that christians make, lol)...but, ofc, as bliblical scholars note, "paul" himself doesn't appear to have had a shred of training when it came to the religion of old magic book.  At best, it's a borrowed ladder that they didn't actually understand and instead inserted their own cultural tropes into..and at worst (and entirely more likely) they tacked old magic book on -after- they'd come up with their new silly religion.  The guy who gave them the idea for a magic book thought that jesus was here to -save- us from old magic books evil god.  

I am saying that you and I live in a post-Christian culture. Christianity was put together out of many various sources, and went on to influence and form the culture we live in. Yes, those sources have roots that pre-date Christianity. But you and I don't. The culture we have now is not a Greek one, it is one that contains Greek ideas via the influence of the church. Unless you feel you have received the ancient teachings in their purity, unaffected by the rest of your culture?

The culture we have now -is-.... significantly, shaped by pre christian ideas...and those ideas continue to persist in our culture. Christianity was made out of them, and just kept incorporating more of them as it moved across the map. It's still doing that. Christianity isn't shaping us, and it never has been..we've been shaping it, and that's why western christianity and eastern christianity are not the same. It's why european christianity and american christianity are not the same. I could keep doing this at every level of colonization.

Yes, yes yes, christians have sworn for centuries that our civilization was built atop their theology, but other than the fact of them saying that..is their any reason that you think it's meaningfully true?