@smileyfacewinkyface Both. If neither story is inspiring you, don't try to force it.
Writing is about noticing something about the world and then figuring out how to communicate that to other people. Whether that's JK Rowling writing about Harry Potter to show how scary and exciting school was for her, or JRR Tolkien writing The Hobbit to talk about what it was like to fight in World War I, all of the best writing comes from what was really going on in the writer's heart.
So, if you're really feeling a bit scared and abandoned, go back to LEFT BEHIND and figure out how to use Prim's life to show exactly what that feels like.
If you're doing new and exciting things, and you're really feeling the rush and danger of it all, go back to TNGA.
And if you're feeling something different, write something different. The point is, even if the situation is fantastic, with aliens, robots, sorcerers, or psychics, the feeling should be real. So, who are you? What do you believe, and how did you come to believe it? How is your life different from most people? What have you noticed, or figured out about the world that most people don't know? And then figure out a situation that illustrates that stuff and WRITE, WRITE, WRITE.