The gospels were written 25 to 50 years after the crucifixion.
Can you believe in the message of the Christ without the miracles? Do you need walking on water and raising people from the dead or casting out "demons" to get the message?
To which message are you referring because the message about having control over weather phenomenon and resurrecting people, etc. would need eye witness accounts.
Only the people Jesus cured in private did Jesus instruct them Not to tell others because Jesus did Not want hear-say accounts but only eye-witness accounts about his works bringing praise to his God.
People actually seeing Jesus perform miracles would help 1st-century Christianity get off to a flying start.
Genuine followers would spread the message of Daniel 2:44 just as Jesus instructed at Matthew 24:14; Acts 1:8.
They would tell others why God's kingdom was a priority to Jesus over healing everyone on Earth - Luke 4:43.
This is because regulating weather, resurrecting the dead, and the global healing of earth's nations will take place during Jesus' 1,000-year governmental rulership over Earth, his millennium-long day of governing over Earth.
Not only will there be ' healing ' for earth's nations as per Revelation 22:2 but even ' enemy death ' will be No more on Earth as per 1 Corinthians 15:26; Isaiah 25:8.
So, Jesus was giving a preview, a coming attraction of what he will be doing internationally in the soon coming future.