Exodus Chapter 23
13And in all things that I have said unto you be circumspect: and make no mention of the name of other gods, neither let it be heard out of thy mouth.
You can talk about "Freedom of Speech" all you want, but God has rules about what you should and shouldn't talk about.
He doesn't want anyone to have any knowledge that there are gods out there that are not HIM. It is dangerous for His children to go exploring after other gods.
God knows that if you KNOW about other gods, your curious nature will always ask "why?" and seek out knowledge. There is a reason God told Adam that he and Eve were not allowed to even TOUCH the tree of knowledge. The old saying, "curiosity killed the cat" has merit; especially in this case.
Many of us are already guilty of breaking this law, myself included. I've studied witchcraft. I've looked up information about Bephomet. I've studied parapsychology and a lot of other anti-biblical subjects. My rationalization is that "You can't fight an enemy you know nothing about", and in some cases, this is true. But, as I reflect on this, I can understand how spiritual subjects can lead others down some very tricky roads.
This is part of the reason God doesn't want you to speak badly of other gods to those who follow them. To speak about other gods, no matter what the purpose, will most likely lead to having a conversation about them with the person you are speaking to. It opens the door for you, yourself, to be influenced by them. God wants to protect you from that.
Once you know the law, however, you are obligated to follow that law, and if you knowingly choose not to follow it, you are aggrivating your guilt.
In today's world, it is hard not to speak about these evils. We see it on TV, we hear it in the news, we see our neighbors practicing them, so how do we protect ourselves from such blatant disregard of God's laws -- particularly this one?
Thank God for Jesus, who died to save us from ourselves! And, in His sacrifice and victory over Satan in this world, He gave us the strength to try to do better!