As part of the Norse cosmological framework, humanity's world—known as Midgard—is regarded as just one of nine realms, all of which are part of a cosmological world tree called Yggdrasil. Different types of being are believed to inhabit these different realms; for instance, humans live on Midgard, while dwarves live on another realm, elves on another, giants on another, and the divinities on two further realms. Most practitioners believe that this is a poetic or symbolic description of the cosmos, with the different levels representing higher realms beyond the material plane of existence. The world tree is also interpreted by some in the community as an icon for ecological and social engagement. Some Heathens, such as the psychologist Brian Bates, have adopted an approach to this cosmology rooted in analytical psychology, thereby interpreting the nine worlds and their inhabitants as maps of the human mind.
According to a common Heathen belief based on references in Old Norse sources, three sisters known as the Norns sit at the end of the world tree's root. These figures spin wyrd, which refers to the actions and interrelationships of all beings throughout the cosmos. In the community, these three figures are sometimes termed "Past, Present and Future", "Being, Becoming, and Obligation" or "Initiation, Becoming, Unfolding". It is believed that an individual can navigate through the wyrd, and thus, the Heathen worldview oscillates between concepts of free will and fatalism. Heathens also believe in a personal form of wyrd known as örlög. This is connected to an emphasis on luck, with Heathens in the U.S. often believing that luck can be earned, passed down through the generations, or lost.
Various Heathen groups adopt the Norse apocalyptic myth of Ragnarök; few view it as a literal prophecy of future events. Instead, it is often treated as a symbolic warning of the danger that humanity faces if it acts unwisely in relation to both itself and the natural world. The death of the gods at Ragnarök is often viewed as a reminder of the inevitability of death and the importance of living honorably and with integrity until one dies. Alternately, ethno-nationalist Heathens have interpreted Ragnarök as a prophecy of a coming apocalypse in which the white race will overthrow who these Heathens perceive as their oppressors and establish a future society based on Heathen religion. The political scientist Jeffrey Kaplan believed that it was the "strongly millenarian and chialistic overtones" of Ragnarök which helped convert white American racialists to the right wing of the Heathen movement.
Some practitioners do not emphasize belief in an afterlife, instead stressing the importance of behaviour and reputation in this world. In Icelandic Heathenry, there is no singular dogmatic belief about the afterlife. A common Heathen belief is that a human being has multiple souls, which are separate yet linked together. It is common to find a belief in four or five souls, two of which survive bodily death: one of these, the hugr, travels to the realm of the ancestors, while the other, the fetch, undergoes a process of reincarnation into a new body. In Heathen belief, there are various realms that the hugr can enter, based in part on the worth of the individual's earthly life; these include the hall of Valhalla, ruled over by Odin, or Sessrúmnir, the hall of Freyja. Beliefs regarding reincarnation vary widely among Heathens, although one common belief is that individuals are reborn within their family or clan.