““Do not let your hearts be troubled. You believe in God; believe in Me as well. In My Father’s house are many rooms. If it were not so, would I have told you that I am going there to prepare a place for you? And if I go and prepare a place for you, I will come back and welcome you into My presence, so that you also may be where I am.”
On the night before the cross, Jesus tells his troubled friends that he is going to prepare a place and will come back for them. The promise of his return was first given as comfort.

