By teaching in parables. Jesus made truth searchable and knowable by anyone interested in honest investigation of His claims. That was the purpose of the parables (see Mark 4:10-12). And Jesus was a master at teaching in this way. He taught with many parables on many occasions. I believe it is entirely possible that much of what He told in parables is not recorded in the gospels. But we have all the important ones that explain the mission of salvation and the person of Jesus.
The interesting factor in this was the attitude of the crowd. This text says that Jesus taught in parables “as they were able to hear it”. This indicates that some may have been in attendance in the crowd, but may have not gotten to the point of the parables. The parables, however, provided two important things that made Jesus’ teaching “stick” in the minds of His hearers. First, as stories, they became memorable. Since we are not an aural society, we don’t appreciate this fact as much. But those who heard the stories in a society of story-tellers, remembered them. It is why we have them now. The second benefit of teaching the parables was that it created a follow-up opportunity. Anyone who wanted to ask for further clarification could do so. Those who investigated were the ones who “heard it”. They could take it further. That was Jesus’ intention all along.
Christian truth is knowable. It is not based on hunches or feelings or pragmatic mysticism. It is real knowledge and truth. Just like I can investigate and understand the periodic table of the elements in chemistry, I can investigate and explore the teachings and person of Jesus. And I can rest assured that the body of knowledge about Him is spiritual truth that is as real as any other body of knowledge. His own words, in His own parables, to His own disciples show me the way to such conviction.