What's The Trouble With His Promise?

John 14:1-3
(1) Let not your heart be troubled: ye believe in God, believe also in me.
(2) In my Father's house are many mansions: if it were not so, I would have told you. I go to prepare a place for you.
(3) And if I go and prepare a place for you, I will come again, and receive you unto myself; that where I am, there ye may be also.