“See that no one knows about this.” (Matthew 9:30)

Then he touched their eyes and said, “According to your faith let it be done to you”; and their sight was restored. Jesus warned them sternly, “See that no one knows about this.” (Matt. 9:29-30)

Why did Jesus 'warn them sternly'?

The text of Matthew prefaces this statement with “Jesus warned them sternly.” (Matt. 9:30). This means that Jesus was serious about them not telling others about this healing event. Why not?

Jesus did not want to have everyone gossiping about the healing. Jesus was not into fame and recognition.

But isn’t this why Jesus healed people's bodies, one might ask? Actually, not. As we can see from this statement of Jesus, together with the previous one, Jesus was dealing with two particular people who had shown their trust in God’s ability to heal them. Thus the healing event took place between God, Jesus, and these two faithful people.

Jesus was not trying to prove to anyone his ability to heal. His focus was on the service of the Supreme Being, and as part of his service, these two men were healed of their blindness.

Why did Jesus heal people?

Jesus' intent was to bring attention to God, not himself.

But that is not what the Supreme Being wanted. Here is the next verse from Matthew:
But they went out and spread the news about him all over that region. (Matt. 9:31)
Just as the loving servant of God wants to bring attention to the Supreme Being, the Supreme Being wants to bring attention to His loving servants. Jesus confirmed this here:
“If I glorify myself, my glory means nothing. My Father, whom you claim as your God, is the one who glorifies me." (John 8:54)
Note also that Jesus healed no more than about 27 people according to the Gospels. This is despite the fact that hundreds of people lined up to be healed wherever he traveled.

As such Jesus, being the loving servant of God, was being acclaimed across the country as a healer not because Jesus wanted the acclaim, but because the Supreme Being wanted to bring acclaim to Jesus. Why?

Because Jesus was focused upon serving God and passing out the message of God - the Teachings of the Supreme Being. Jesus confirmed this:
“My teaching is not my own. It comes from the One who sent me." (John 7:16)

What does this say about Jesus?

We might compare the situation to the ambassador of a government. While the ambassador may be a shy person, the government he or she represents will give them a special office in a special building - the embassy - in another country. 

The government the ambassador represents will also support him and promote him while he is representing the government. Why? Because the ambassador's focus is to serve the government and its people, so the ambassador's government will support those services.

This is similar with respect to God's representative, except for the fact that the position of God's loving servant is not a paid position. It is based upon a loving relationship. God's representative loves the Supreme Being and thus acts on His behalf as loving service. This is how Jesus defined himself.

Furthermore, God has the ultimate ability to empower His representative. He does not need councils and assemblies to authorize His representative. Jesus was an exemplary representative of God. He was God’s confidential servant. Jesus sacrificed his entire life and existence to please the Supreme Being:

He confirmed this in this statement:
“My food,” said Jesus, “is to do the will of him who sent me and to finish his work." (John 4:34)