When Jesus "began to preach and to say, 'Repent, for the kingdom of heaven is at hand'" (Matthew 4:17), most people didn't understand His message. The reason is quite simple: He purposefully spoke in a way that hid key aspects of the truth. Though multitudes of people thronged to hear Him, most didn't comprehend what He was saying about the Kingdom of God.
Jesus' teaching style—authorative and unlike the scribes—attracted people's attention (Matthew 7:29), and many came to be healed of physical ailments (Matthew 14:35-36). Others likely came hoping to see a miracle or watch Jesus verbally get the best of the religious authorities or possibly a free meal (Luke 23:8; Matthew 15:1-20, 29-38; 14:13-21). But most didn't fully grasp what He was saying. While they couldn't deny the miracles and were intrigued by His style of preaching, His message was a mystery.