I've long realized that the doctrine of the ransom sacrifice, as taught by JWs and other Fundamentalists, is completely insane. It implies a God that is self-inconsistent and far more concerned with his own self-image than with minor concerns such as justice and mercy. By this I don't mean that there might not be some logic to this ancient notion, but that every claimed explanation I've ever seen, including that in the Bible which originates the idea, has huge holes in it. I've asked some of my dearest Christian friends -- not JWs -- to try to explain it, and they are always reduced to "the dog ate my homework" sorts of rationalizations.
Basically, the ransom sacrifice doctrine states that "bad things must come in pairs". In other words, Adam did a bad thing, and the only thing that God would accept to cancel out that action was another bad thing. This is patently insane. Most Fundamentalist Christians are unable to understand why.
The doctrine really says that divine justice is a farce. God sees Adam do a bad thing, and decides that someone ought to pay for it. Doesn't matter who -- just that someone must pay. Adam is mysteriously disqualified from paying for it, so God has to figure out something else. He decides that if he works his divine magic such that his Son is somehow turned into a human being -- which idea causes a host of other problems -- and then killed unjustly, this will somehow cancel out Adam's "sin".
Unfortunately this is something like if your younger son raped your granddaughter, you decided that offering your older son the opportunity to die to "atone" for the younger son's sin would make everything alright (of course, you've already killed your younger son). Your older son accepts, and so you arrange for a kinky hit man to hang him on a meat hook and torture him to death. But you have magical powers, and so a couple of days later you "bring him back" and everything is hunky dory. Can anyone not see why such a scenario is totally farcical? Can anyone not see why the "ransom sacrifice" doctrine is equally farcical?
You might find my rather long essay on this subject, "God's Justice: Sin, Imperfection, and the Ransom Sacrifice", at http://www.geocities.com/osarsif/index2.htm of some interest.