While he was still speaking, there came from the ruler’s house some who said, “Your daughter is dead. Why trouble the Teacher any further?” But overhearing what they said, Jesus said to the ruler of the synagogue, “Do not fear, only believe.” And he allowed no one to follow him except Peter and James and John the brother of James.
Mark 5:35-37 ESV
Unfortunately it seems it was too late for Jesus to save Jairus daughter, however even when he heard that Jairus’ daughter is dead, Jesus wasn’t sad, but instead he confidently reassured Jairus that he shouldn’t fear, but instead believe. Indeed, the opposite of fear is to believe :) When you believe in God, you don’t need to fear of death! For Jesus is Lord and sovereign even over death!