Who is that Influence? Why Alexander the Great, of course. Why was he such an important influence on the development of Judaism (and later on an influence on early Christianity)?
Because he conquered much of West Asia and opened the way for Hellenic (Greek) culture to influence both Judaism and early Christianity.
So what killed this relatively young man? Previous theories often saw alcoholic poisoning as the likely reason.
But Dr Katherine Hall, ( A senior Lecturer at the Dunedin School of Medicine NZ and a practising clinician) claims that the most likely explanation, is that Alexander died as a result of a neurological disorder Guillain-Barré Syndrome (GBS).
DR Hall collected all the extant ancient information on Alexander's death and argues that GBS offers the best explanation.
You can read the abstract for her paper in the current bulletin of The Ancient History Bulletin. If you want to read the full paper, it will cost you $1 (its an Open Access Journal)
Abstract: "The most striking feature of Alexander the Great’s death is that, despite being extremely unwell, he was reported to have remained compos mentis until just before his death. Combined with evidence that he developed a progressive, symmetrical, ascending paralysis, it is argued that he died from a sub-type of the autoimmune disorder, Guillain-Barré Syndrome (GBS), most likely induced from a Campylobacter pylori infection. GBS could also account for the reported lack of decay of his body, and his death may be the most famous case of pseudothanatos, or false diagnosis of death, ever recorded.""
Of course, we will likely never really be able to confirm what killed Alexander, but GBS seems to fit.
Footnote: If Alexander had not conquered West Asia, those young Levites ( in Maccabean times) in the temple, may not have wanted to get naked at the local Greek gymnasium or try to disguise their circumcised penises. Greek may not have been spoken by any early christians, And Paul may not have decided that he could get better results from preaching to gentiles than to Jews.