By the end of the film she is so certain of his identity and of his love for her that she is willing and able to jump off the Brooklyn Bridge into the unkown. She chooses the leap of faith into 1876 instead of staying in 2001 and accepting the job promotion that she had wanted so badly.
Charlie asks the same question about Leopold. At first he believes Leopold to be an actor who remains “in character” all the time. When the situation gets more serious – his sister’s heart is on the line – Charlie grows more concerned and asks Leopold directly who he is. He remains unconvinced of Leopold’s identity until he sees the photographs that Stuart had taken during his stay in 1876.
By the end of the film, both Charlie and Stuart know exactly who Leopold is, and they are helping and encouraging Kate to take the leap of faith.
People were also divided about who Jesus was when He stepped out of eternity and into time. Jesus and his disciples were discussing all the conflicting opinions regarding the true identity of Jesus.
If you believe He is who He says He is, then how does that affect your life?