Christians are as sheep among wolves but we must beware of wolves among the sheep. There is no room for wolves in the Lord’s flock. The shepherd who believes in that kind of peaceful coexistence is not a shepherd but a hireling.
You might as well try to describe a sunset to a blind man, play music for a deaf man, talk to a dead man, as to discuss the deep things of God with an unconverted sinner. “…the natural man receiveth not the things of the Spirit of God…” (I Corinthians 2:14). We might as well try to catch sunbeams with a fishhook or talk nuclear physics with a monument in a city park. The most erudite Ph. D. cannot take it in any better than a hillbilly; it is casting pearls before swine. As far as spiritual realities are concerned, a man who has not been born again is blind and can’t see, deaf and can’t hear, dead and can’t feel.