Paganism
Greek Paganism
Certain deities, in particular Zeus and Poseidon, were never depicted by images during the Archaic period (cit. A History of Pagan Europe, ch 2, pg 85)
Roman Paganism
Varro tells us that the early Romans worshipped their deities without images. The basic Roman belief seems to have been in numen or supernatural power rather than in personified spirits (cit. A History of Pagan Europe, ch 3, pg 52)
The god Mithras, as acceptd in Roman religion, was changed from the original Persian role of a mediator between the god of light and order, Ahura-Mazda, and the one of darkness and chaos, Ahriman.
Nordic Paganism
The viking leader Ragnar Lodbrok is today celebrated as a martyr by contemporary followers of Asatru (cit. A History of Pagan Europe ch 7, pg 125)