Wasn't that just a test to see if Abraham would actually do it?? If I'm thinking of the right Biblical story, then Abraham prepared his child for sacrifice and was ready to do it when God intervened and said that it wasn't necessary. It was just a test to see if Abraham was loyal and willing to do whatever God commanded, and when God saw that he was, He stopped the sacrifice.
I don't think that God would consider child sacrifice an appropriate form of worship. Children are gifts from God and should be treated as such.
As for JWs and the whole blood issue, they somehow manage to take great pride in the fact that they are willing to sacrifice themselves and their children for "the Truth". I've seen pictures of the issue of their magazine that had pictures of children who had died from the lack of a blood transfusion on the cover, with a headline that said something about how they died for their beliefs and for God. Somehow, that really doesn't seem like something to be proud of to me.
God doesn't want us to die senselessly, He wants us to live, and to me, dying because you refuse a blood transfusion based on an organization's rules seems pretty senseless to me.
In my faith, I believe that donating blood is a beautiful gift to help others, as are organ donations, and I am a card-carrying blood donor and organ donor. Deeds like that, giving blood and organs, will help save countless lives. Now that's something to be proud of.
-Becka :)