Hi TD!
Thanks for contributing the scripture for the illustration. I have no doubt that is the scripture being portrayed in the illustration. What I am saying is that these blood rituals seem to have been in place for thousands of years and in most every culture. It seems to be a prevailing concept of secret societies and religions alike.
What exactly is all this blood shed for? What is this blood covenant all about?
Blood Covenant
The purpose of the blood covenant is to bind two individuals, families, or tribes together. The covenant was cut in blood to demonstrate that it was to be an everlasting covenant. The life or spirit of a man, according to the scriptures, is said to be in the persons blood itself.
A blood covenant ...represented an eternal bond between the two bloodlines. In a blood covenant, the two bloodlines were believed to be merged together into one.
(There is more going on here than what has been revealed to the outsiders. Who are these two bloodlines? Is it a covenant between humans and angels? Is it a covenant between humans and a blood thirsty demon?)
The slaying of the sacrificial animals left a pool of blood. The two entering into covenant would often stand in the midst of the pool of blood, their bare feet being immersed in the warm blood of the slain animal(s). It is while both were standing in this pool of blood that the ceremony would take place. The blessings and curses were usually stated while standing in the blood. It was understood that each representative would do his utmost to perform the vow of the covenant, even if it should cost him the same price that it has cost the sacrificial animal, the shedding of blood and the very life of the creature.
This was to ensure that the blessing would come to the other party, no matter what it might cost. When the curses were pronounced, the slaughtered animal would represent the cost to each party for willfully breaking the blood covenant. Because tribes were joined by such blood covenants when trust and faithfulness were of paramount importance, the curse was pronounced. The willful breaking of the blood covenant would initiate the beginning of a tribal war or feud. To willfully break the covenant meant that the guilty party must be slain as the sacrificial animal had been slain.
http://revelationofjohn.com/Marriage.html