The Bible often describes evil people as animals, such as pigs, dogs, snakes, worms, lions, bulls. In this particular portion of scripture, we are warned about those who are spiritually dogs and pigs. How are we to deal with these types of people? We are not to set before them the precious things of God, namely, the Gospel. There is a place not to give some people the Gospel truths as all they will do is trample on it.