The two most significant rituals that we as Theodsmen undertake are blót and sumbl. Blót, of course, is the ritual offering of an animal and its blood to the Gods. When a non-animal offering is made, it is referred to as a fórn, but the significance is similar for purposes of this essay.
The function of blót (or fórn, but I will stop making that distinction and use the former term as a shortcut with the understanding that both are intended) is to establish a connection between the Gods and mortals. By making the offering, we are at once demonstrating our loyalty to the Gods and setting up an expectation that They will reciprocate by increasing our luck and prosperity. In a Theodish context, this is done corporately; at the level of the tribe, or clan, or family. The blót is designed to reinforce that connection between men and Gods. The blót extends beyond the boundaries of the tribe, to touch the Gods.
Sumbl is another story entirely. At sumbl, we reinforce the bonds within the tribe, or clan, or family. It is there that oaths are made and sworn, alliances formalized, marriages established, and so forth. It is also there that individuals are able to establish their own gefrain, through the toasting of their ancestors and boasting of their past and future deeds. It is significant that such is done in the company of the other participants at sumbl; the intent is to touch those participants. The sumbl rests squarely within the boundaries of the tribe, to build it from within.