Here's a shocking article about a mother who murdered two of her children because God commanded her to. She's now on trial. This incident reminds me of the Bible story about Abraham being commanded to sacrifice Isaac. I find that story disturbing. (I can't agree with Elder Monson's strange assertion in a 2002 conference talk that "All of us love the beautiful account from the Holy Bible of Abraham and Isaac.") Apparently, sometimes it is possible for a good person to fully believe that God is speaking to them when really he is not. My advice to anyone reading this: even if God tells you to kill someone, don't do it.