But it has already been shed. The author of the article and some of the posters here seem to think that the shedding of blood is an ongoing process; that there is literally a big bowl of blood up in heaven that will be used to literally wash away our sins.
I agree with our Calvinist friends that our sins were washed away on Mount Calvary. The work was finished there.
Bible literalists are irritating. Some parts of the Bible are intended to be taken literally, but not all.