Greek culture emerged as the dominant force shaping religious deviation in the ancient world following the conquests of Greek armies roughly three centuries before the New Testament era. This military conquest was accompanied by a cultural imposition so attractive that even the militarily and economically powerful Romans, who dominated the first century world, admired and deliberately copied it. Through Roman expansion, this Greek cultural influence spread to regions the Romans controlled, including the Israelitish peoples who had by then settled in Northwest Europe. As a result, the philosophical concepts of figures such as Pythagoras, Thales, Socrates, Plato, and Aristotle became embedded as cultural guides throughout much of the modern Western world. This Greek philosophical tradition became the primary resource for what religious scholars label Gnosticism, and it was Gnostic thought—rather than Egyptian or Babylonian influence—that posed the strongest doctrinal challenge to first-century Christian teaching. Central to this challenge was Plato's Theory of Forms, still taught in modern universities, which held that earthly things are mere shadows of perfect, unchanging heavenly archetypes. This Platonic framework was absorbed by Gnostics, who taught that humans could attach themselves to the heavenly realm (the pleroma, or "fullness") through elemental spirits or angels, thereby achieving spiritual perfection and immortality apart from any biblical law. The Gnostics, drawing on this Greek philosophical inheritance, viewed the material earth as evil and, since Yahweh created it and authorized the seventh-day Sabbath, concluded that Yahweh Himself, the Old Testament, and the Israelites were all evil. This hostility to Yahweh persisted even among Gnostics who infiltrated the Christian church, producing what Paul calls "the mystery of lawlessness" in II Thessalonians 2. Their doctrine included believing Christ was only partially spiritual while on earth—contaminated by "the Hebrew religion" because of His Jewish observance of the law—until His return to the pleroma restored His full spirituality. This Gnostic distortion reverberates into modern Hellenistic Christianity, surfacing in doctrines such as the elevation of Mary and the notion that Jesus kept the law only because He was a Jew, a claim underlying modern dispensationalism and eternal security teachings. The most extreme Gnostic teachings, such as the symbolic evil assigned to the number seven (the Sabbath) versus the good assigned to eight (Sunday), were eventually rejected by church leaders in the second through fourth centuries AD, yet the fundamental shift to Sunday observance—rooted in this Greek-derived Gnostic hostility toward the Sabbath and the Creator—was retained and eventually imposed by imperial edict following the Council of Nicea. Thus Greek culture, through its philosophical legacy absorbed into Gnosticism, provided the ideological foundation for the church's departure from Sabbath-keeping to Sunday worship, a shift whose theological groundwork is already visible in Paul's warnings to the Colossians around AD 60, decades before the formal change took effect.