There is a rather misleading statement contained in Tacitus' Germania in which he states regarding idols of the Gods:
"In other matters, they judge it not in accord with the greatness of the gods to confine them with walls or to liken them in appearance to any human countenance. They consecrate woods and groves, and the mystery that they see only in their awe they call by the name of gods." (Germania 9.2, Rives translation)
"The Germans do not think it in keeping with the divine majesty to confine gods within walls or to portray them in the likeness of any human countenance. Their holy places are woods and groves, and they apply the names of deities to that hidden presence which is seen only by the eye of reverence." (Germania 9, Mattingley and Handford translation)
We do know from archaeological excavations that the ancient Germans did in fact possess idols of the Gods and as I have already demonstrated in earlier articles they also built temples for the worship of the Gods. Anthropomorphic wooden idols have been found in Germanic speaking areas going back as far as the Bronze Age. A good example of such an idol is the Broddenbjerg idol which dates back to the 6th century BCE and discovered in a peat bog in Viborg in Denmark. These idols are known as ithyphallic(the male variety of course) and referred to as Pole Gods. There are female versions of these wooden idols as well. Such idols were not confined to the Germanic peoples but are also to be found in formerly Celtic speaking and Slavic speaking areas, indicating that this was a northern European religious feature.
Rudolf Simek (Dictionary of Northern Mythology) is of the opinion that Pole Gods were known as early as the European Stone Age and thus represent probably one of the most archaic expressions of Germanic and Aryan religiosity. He conjectures that the Pole Gods may in fact be connected in some way with the Irminsul. Perhaps theses were smaller variations of this cult.
Tacitus does contradict himself as elsewhere in Germania 40 he refers to the sacred grove of Nerthus and the implication is that She was represented by an image, cared for by Her priest. Perhaps Her image was more elaborate than that of the Pole Gods.
Going forward to 11th century Iceland we have the bronze figurine of the Eyraraland Thor holding a Hammer which strongly resembles the famous Foss Wolf's Hammer. The Icelandic sagas frequently refer to temple images of the Gods. Adam of Bremen in 1070 wrote about the golden images of three Gods; Thor, Wodan and Fricco in the Uppsala temple in Sweden. So clearly the Germanic peoples consistently used idols or images of the Gods as part of their religious practice from the Stone Age to the Mediaeval period. Such practices continued in the Baltic lands right up to the 16th century.
I believe that it is a misunderstanding to say that the Germanic peoples literally worshipped these figures made by their own hands. This is a typical accusation made by xtian clerics. What they fail to understand is that these figures represented the Gods symbolically. Nigel Pennick explains this very well in his Secrets of the Runes. In discussing the mysterious force known as Ond he states that it can accumulate in sacred images and worshippers are in fact accessing the reserves of Ond located in the image, the inner essence in other words. This same energy may be found in sacred wells, groves and stones.