When Heimdall came to men, his desire was to help our people develop a civilization. In doing so he allowed us to understand a model that all humans will live by. No matter how we develop our societies, these models are always there, always in the background. People can create fantasies about 'equality' and utopias, but you will never be able to remove the classifications given to us by the Gods themselves. Some have even tried to remove them with the murder of millions of people and they were still unsuccessful. Of course, I am talking about the three castes or classes of men.
These classifications are not only natural, they are sacred to us. In the end you cannot defeat nature, and you cannot overcome it.
Our technology and our civilization may fool us into believing this to be the case, but in the end we will always be subject to its laws. From the ancient Vedic system to that of Rigsthula, we are taught that the Gods blessed all three classes, though a definite distinction was made. The idea is that, even though we are all connected and should be good to one another, there should be recognition for the various stations in life. The idea is to not covet another's placement, but rather to be happy with how our own wants and desires place us within the spectrum.

Thralls: When Heimdall traveled to the three homes of the parents of each class, each one provided him with a different mode of hospitality. This hospitality could be viewed as a ritual offering to the God and the progeny that came from such offerings reflect the gifts originally given. This becomes a powerful symbol that we can look at within our own ceremonial model. Ai and Edda gave what they could within their capabilities. "Then Edda took a loaf from the ashes, heavy and thick, and mixed with bran; she laid more than this on the middle of the board, broth was set on the table in a bowl, there was broiled calf, a most excellent food." (XX.47) Because of this offering, Heimdall blessed their union and from this came the son Thrall, the progenitor of the Thrall class.
The Thralls represent the lowest class, but are still given the blessings of the divine. They are to work the fields and serve the other classes in their duties. Using Indo-European comparisons we can also see the idea that the lowest class is built upon base desires. Theirs is the class of pure physicality. Their desires and relationships are focused solely upon pleasing their bodies and identifying their base natures as a higher attribute of the Self, when in fact it is nothing more than an aspect of their own narcissism. The Thrall wants what they want when they want it, and would resent anyone for denying them this, ever.

Karls :The next class is that of the warrior, which blends the two elements of the physical and the mental to create a balance of discipline and fortitude. The Karl is the one willing to make sacrifices for the greater good, who understands the necessity of conflict, and yet also hones his/her physical prowess into a mighty weapon. When Heimdall came to the home of Afi and Amma, they gave him their hospitality (the verse describing the meal offered is missing in the text), and because of what they gave they were blessed with the son named Karl, who became the progenitor of the Karls. Karl became a farmer, and held the position of a Freeman, although later the role of the Housecarl (Húskarl) came to designate a warrior. So, he is the one that will take matters into his own hands, who is not afraid to get dirty, and will gladly face the foes of his people when threatened. That is his calling, and that is his place within the social strata.

Jarls: Finally, there come forth the leaders. The intellects are an important part of the structure because we need people that can formulate the ideas, develop the strategies, and design the layouts. Heimdall came to the home of Modir and Fadir, and he received from them a sumptuous feast and the greatest of conversation and hospitality. Because of this, their family received the highest gift of not only a heroic son, named Jarl, who would lead soldiers on the battlefield, but later the boy that would become the first king, named Kon. From Kon the Young's name we get the very word "King" (Konung). They also received the power of the runes, through him. Kon went under the tutelage of Heimdall and from him learned the Aefinrunar and Aldrunar or "Runes of Eternity" and "Runes of Earthly Life." As stated, we believe that these were not only the runes themselves, which would have brought them a written language, but also the notions of religion and social development. Because of this, the Jarl represents the embodiment of all three aspects of the classes: the physical, the heroic, and the intellectual. This is the class of the Godi/Gydja, the leader, the builder, the designer of great things, and the general on the battlefield.It is our place as a religious people to not only identify our station within the community, but also to recognize the elements of those around us. Not everyone is going to be a leader, and not everyone is going to be able to move past the level of Thrall. Even though this latter connotation has developed into a negative, it is important for us to note it because when we allow obvious Thralls to become leaders our civilization will only face the worst of moral decay and corruption. When laws are passed and people are made subject to the base desires of those obsessed with the physical, then they will automatically lead us on a downward spiral. One may advocate for a "purely natural" ideology simply to denounce honor and integrity, or they may seek to develop movements based solely upon sexuality, or they attract themselves to the most despicable ideals in order to remove any sense of loyalty and values from the system you live by. Be wary of this. Know them by name. See them for what they are.

From: https://skjalden.com/viking-social-classes/