The Nordic Bronze age was a time (1730-760 BC) was a time of prosperity in the far north. It is yet another example of a group of people who were very successful in their day, being almost vanishing after their collapse. Although some of their religion likely made it into the proto-German cultures of Jastorf and Pomerania, most of what we know of them is from archeological and linguistic investigations.
from Jean Manco, Ancestral Journeys, Thames & Hudson LTD, London , 2013, pps. 210-211.
...[T]he Nordic Bronze Age [was] the cradle of Proto-Germanic [language and colure]. It was a comfortable cradle for many a year. The Nordic Bronze Age began in a welcoming warmth. An earlier climate shift made southern Scandinavia as warm as present-day central Germany. Groups of people from the wide spread Corded Ware and Bell Beaker [pottery] cultures had moved north into Jutland and the coasts of what are now Norway and Sweden. There they melded with descendants of the Funnel Beaker and Ertebolle people into a rich Bronze Age culture. The wealth and technical excellence of its bronze objects is impressive. Trade was important to this society. So was seafaring. Voyages linked Jutland and Scandia into one communication web.
However, the climate gradually deteriorated, bringing increasingly wetter and colder times to Jutland, culminating in so steep a decline in the decades around 700BC that much agricultural land was abandoned and bog built up . Pollen history reveals a similar picture in southern Sweden. Around 500 BC forest encroached on areas that had long been farmland. Meanwhile an influence from eastern Sweden reached the southern Baltic shores in the Late Bronze Age, providing a clue to where some of the Scandinavian farmers were going.
The advancing cold left most of their homeland lightly populated with Sami reindeer herders pushing into some of the abandoned areas. In Scandinavia, this period is often called the Findless Age due to the lack of archeological finds (source). The cold spell, no doubt caused a lot of tensions with the iron age Celts on their southern border. In events unrecorded in history, the two groups appear to have merged in an area just south of the previous Nordic territories and formed the group that was to give rise to the Germanic folk. The Nordic Germans and Swedes apparently moved back into Scandinavia at some later point when the climate warmed up again.