There was a time when peoples' prime association on earth was with animals of one sort or another, for not only were they involved in animal husbandry, and were intrepid hunters they even took animals to their place of worship; and sacrificed them to their gods, and even formalised rituals where the meat and blood held important places in their ceremonies. Even true worshippers of Almighty God were not exempted from such animal rituals and volumes were written to guide them in the best ways to proceed and what to do with the meat and blood and who was to do what and when and such like. Anyone can examine how entrenched these practices were by taking a look in the Bible at a passage like Numbers 19: 1-22 for example; to see how meticulous and comprehensive were the arrangements for such rituals.
This association with animals was so powerful and the ritual of cleansing, like that involving the red heifer, so significant that the Bible gave it an importance that was unearthly for it said this:
"And a man that is clean shall gather up the ashes of the heifer, and lay them up without the camp in a clean place, and it shall be kept for the congregation of the children of Israel for a water of separation: it is a purification for sin." (Numbers 19:9) Notice that this water from the ashes of a red cow was "a purification for sin" although it was efficacious only in the physical sense; to cleanse one from contamination who had contact with a dead body.
This practice of purification for sin was done throughout Israel's history until the Temple was destroyed in AD 70 and history shows that the ashes of the first red cow lasted a thousand years (until the time of Ezra) and a total of nine in all were killed and burnt to form the ashes.
Believers know and has experienced a new and better relationship to do with the "purification for sin", one that transcends the blood of any animal whether that animal be a cow, a goat or a sheep or a bird or any other creature, and the Bible puts it in beautiful words like this:
"For if the blood of bulls and of goats, and the ashes of an heifer sprinkling the unclean, sanctifieth to the purifying of the flesh: How much more shall the blood of Christ, who through the eternal Spirit offered himself without spot to God, purge your conscience from dead works to serve the living God?" (Hebrews 9:13-14)
And the Apostle John made it quite clear that this facilitation was not exclusively for just a few privileged people but for all humanity when he said:
"And he is the propitiation for our sins: and not for ours only, but also for the sins of the whole world." (1 John 2:2)
Nevertheless they are many who will not avail themselves of this graciousness from above and would rather cling to their sins even although they know to do so brings death. Freewill is involved and it is regrettable that knowing the right way does not always result in choosing that way for such is the tragedy of the human race. No matter how good the plan...