"I believe that neither I nor anyone else in this world could describe the strange scene that followed - solemn, somber, melancholy, terrible, and yet tender." -- this is how Seward tries to show us the affectionate passion of the Harkers
After everyone makes the promise to Mina about her death, Jonathan asks her:
"Must I also make that promise, my wife?" Mina answers him (this part brings tears to my eyes every time I read it) "You too, my love. And you must not hesitate. You are the one I love most, you are my world. Our souls are united forever and ever, for eternity. Remember, my love, the brave men who in times past killed their wives so that they would not fall into enemy hands. Their hands remained steady, for the women themselves begged to be killed. It is a man's duty, in turbulent times, to those he loves! And, my love, if I must be killed, may it be by the hands of the one who loves me most. (…) If that time comes, I count on Mr. "Van Helsing" to ensure that my husband will keep for the rest of his life the happy memory of having been the one to free me from this terrible curse."
The climax of the scene is when he asks Jonathan to recite the Office of the Dead as a way of keeping his beloved's voice in his memory:
"I would like you to do this for me, my love, because I will carry with me forever the memory of your voice, no matter what happens!"