If Jesus taught the crowds in parables and never said anything to the crowds without a parable, the obvious question is "what were the parables about?" Were they about faith in Jesus? Were they about being baptized and going to church? Were they about love? Since Mark's gospel has few of Jesus's teachings, it is interesting to turn to Matthew's gospel to see how the parables in Matthew's gospel are introduced
MT 13:44-48: "The Kingdom of heaven is like this. A man happens to find a treasure hidden in a field. He covers it up again, and is so happy that he goes and sells everything he has, and then goes back and buys that field. Also, the Kingdom of heaven is like this. A man is looking for fine pearls, and when he finds one that is unusually fine, he goes and sells everything he has, and buys that pearl. Also, the Kingdom of heaven is like this. Some fishermen throw their net out in the lake and catch all kinds of fish. When the net is full, they pull it to shore and sit down to divide the fish: the good ones go into the buckets, the worthless ones are thrown away."
Comment: The parables are about the Kingdom of heaven (see also [we should put links here--DE] MT 13:24; MT 13:31; MT 13:33; MT 22:2; MT 25:1; and MT 25:14) and it is by examining the parables that one can get a glimsp of some of the characteristics of this Kingdom.