"If you love her enough to give up your world for her, don't you think she would want to do the same for you?" Pairs with "People are willing to make sacrifices for the people they care about."
This is because the person speaking is actively talking about someone sacrificing their "entire world" for someone else.
"She looked around at the stars, the moon, the trees. These were things she could count on." Pairs with "Nature can be a source of courage and comfort."
This is because the stars, moons, and trees are all a part of nature. The woman looks around her and finds comfort in these things because she can count on them.