Jesus was a masterful teacher. In Mark it says, “With many such parables He was speaking the word to them, so far as they were able to hear it; and He did not speak to them without a parable; but He was explaining everything privately to His own disciples” (Mark 4:33-34 NASU).
The things of God are not as easily understood as the trade of being a mechanic. That is why we need Christ in our hearts if we want to understand him. He only reveals Himself to his own.