“This something you believe or something you can prove in court?”
There were thousands of eyewitnesses to Christ’s existence and various miracles. Several testimonies are well recorded and preserved.
People have been sent to the death chamber on the testimony of two or three witnesses!
If the several written and historically corroborated witnesses do not convince you, I don’t know what would. That was God’s purpose in having the accounts of Jesus’ life recorded.
People will form opinions about ancient history on the scrappiest of evidence and documents. Jesus’ life and ministry are far better documented than Hammurabi or King Tut or Genghis Khan or Confucious or Caesar. Why believe the dinky history of others and disbelieve the quantity of history about Christ?
All true, but don't forget that Scriptures teach that even when Jesus performed these miracles, there were people who witnessed them with their own eyes and still refused to believe. On top of that, the Parable of Lazarus and the Rich Man teaches us that Scriptures are all the "proof" we need of God being real, and that if people won't believe on the account of the Scriptures, they won't believe even if someone rises from the dead.