"Faith is the fuel for the soul’s journey. Without belief in greater ideals, we are incomplete – the union of the spirit with the flesh is what raises us above beasts and inhumans.”
The First Heretic – Horus Heresy Book XIV
Biology is the most important factor in the shape of a civilisation. Religion is not the primary factor. Thus Christianity did not create Europe. Western civilisation stems from ancient Greece (or Rome, depending on who you ask).