As I was putting Max to bed just now, he whispered to me "I'm Jesus sick". I clarified, "Jesus sick?" "Yes." I asked him what that meant. His response, "I want to be in heaven."
So, I suppose Jesus-sick is like homesick, longing for and missing Jesus. Leave it to a four year old to articulate it so well.
I think I'm feeling a little Jesus-sick tonight, too.