First-century Christians were pious, Torah-observant Jews who debated minutiae of Jewish law — making wholesale borrowing from pagan myths implausible

The earliest Christians were pious Jews who debated whether believers could eat meat sacrificed to idols, whether Jewish and Gentile Christians could eat together, whether Gentile males needed circumcision, whether Jewish Christians must maintain temple purification rites. These same people would not have wholesale borrowed pagan myths to form the foundation of their new religion.