I completely agree with the above editor about the Biblical allusion. That is a very astute response.
Also, this passage in Brave New World is Huxley's attempt to stir us, the readers, into a rebellion. As a member of the counter-culture, Huxley wants his readers to throw away their soma in all its various forms as well.
So, what is modern-day soma? And how can we throw it away? For sure, it's that which is frivolous, addictive, and distracting--that which enables us to escape reality. I see it as entertainment in general (TV, movies, internet, video games, sports, pop music). Also, it's that which is habit-forming physically: junk food, smoking, alcohol, pharmaceuticals (legal and illegal). Aren't these materialistic things that which our culture values most?
If Huxley were still with us, would he not agree that we're losing the will to rebel against modern-day soma? Just as Jesus might be disappointed that we've turned our temples (bodies) into dumping grounds of materialism, I think Huxley would be angry that we're all regulated by pleasure and entertainment.
To me, it is similar to the part in the Bible where Jesus turns over all the tables of the money lenders in the temple in Jerusalem. I think that both of these acts have the same message.
In both cases, the acts are meant to try to tell the society that it is losing the proper values -- it no longer values the things that it should. In John's case, he is in a hospital where people go to die. This should be a solemn place where people's emotions are honored. But this society is trying to do away with emotions. Instead of emotions, it gives people drugs to kill the emotions. By trying to throw away the drugs, John is symbolically throwing away society's control over and denial of people's emotions.