Let me put this to bed....if you are a Christian then you probably follow the Bible's teachings like Matthew 7:6. Which in its literal and figurative meaning is exactly what we are talking about.
Give not that which is holy unto the dogs, neither cast ye your pearls before swine, lest they trample them under their feet, and turn again and rend you.
Basically, don't preach to creatures who you know won't listen out of ignorance or ability to reason.
It's always fascinating to discover which parts of the Bible Christians choose to read literally and which parts they choose to read metaphorically. So who decides this? Jesus?