Thor (Old Norse Þórr, Old English Đunor, Old High German Donar, Proto-Germanic *Þunraz, “Thunder”) is one of the most prominent figures in Norse mythology. He was a major god of all branches of the Germanic peoples before their conversion to Christianity, although he reached the height of his popularity among the Scandinavians of the late Viking Age.
–from Norse Mythology for Smart People by Daniel McCoy
Everybody tells me they love Thor. But these days, it is more likely Chris Hemsworth, star of the Marvel Thor movie franchise, that they mean.
Thor is one of Odin’s sons. Odin is known by many names, including Allfather, which suggests he is the father–or at least the eldest and wisest–of all the gods. For both reasons, it would seem Odin is the more powerful of the two. But that isn’t necessarily so.
Odin appeals to those seeking the power to rule, to divine the future, to use magic to change what is. He travels around the cosmos, often in disguise or at least using names to hide who he is, in search of knowledge and wisdom. He demonstrates his power through wit and ability to out-think and out-maneuver those he encounters.
Though one tale exists where Thor dresses as a woman in order to regain his hammer, in general Thor travels without disguises. He is easily identified by the two goats who draw his chariot and his hammer ever at the ready. Thor appeals to those who wish to rain down might on their foes in order to defeat them.
Those in power may wish to appeal to both gods. Those not in power look to Thor for protection.
Old Norse society was generally divided into three classes: those who ruled, those who battled, and all the rest including those who farmed, fished, built, or served others. Odin appealed to the first group–those who ruled (or wished to rule). Thor appealed to the other two classes. Over time, the number in the first class grew smaller while the other two grew larger.
Perhaps for that reason, by Viking time, Thor’s popularity exceeded Odin’s. As the Viking timeframe overlapped with the spread of Christianity across northern Europe, it appears Thor’s hammer, Mjöllnir, became a symbol of resistance against Christianity. While converts to the new religion wore crosses around their necks to announce which religion they followed, people of the Viking era wore amulets in the shape of Mjöllnir around their necks.
Another explanation for why people of the Viking age might have equated the wearing of Thor’s hammer with Christians wearing crosses is that Thor used his hammer not simply in battle to defeat enemies. His hammer also was important for hallowing the ground to ensure bountiful harvests.
No wonder people love Thor.
 Orel, Vladimir. 2003. A Handbook of Germanic Etymology. p. 429.