See here (all linked). Blood atonement belief and concept already covered. No need to re-invent the wheel, and go in more circles.
Remember, 'blood' is symbolic.
You can have faith in any thing or substance, but the only faith that avails is that placed in 'God' alone, as you would agree. Exalting the blood of a man as something magical or divine in power, can distract one from a more original and universal power, that of God (Spirit) alone. Only that Spirit is Life. We can assume 'blood' is a symbol for the life-plasm of the Spirit, as it gives life to flesh, but this is allegorical.
Faith can be placed in things or substances, but these are secondary or mere accessories in one's religious culture, practice or mythology. We consider metaphors, archetypes, shadows, allegory and the like. Such is the play of language. Such personal affections or assumptions have their place, but when exalted to the status of absolute truth, these becomes 'idols' more or less. They are only relative terms and meanings within the Greater Whole.
pj
How's that "Saucer" of yours working out for ya?