What would be a term for something/somebody that gives a person confidence, motivation, strength or hope in times of trouble? The scenario I have in mind is of a person facing a real life-death situation, they're absolutely overcome by the atmosphere at that moment, to act at such a time seems almost impossible/worthless to them. Then suddenly they get a glimpse of the most important person/thing that matters to them. This inspires them to act and fight in that situation. How would we describe this person or thing? A motivator seems a rather uninteresting or dull term to me. Following two scenarios might further help understand the nature of the person/thing in question.
1) Jenna is a middle-aged woman, fighting cancer, her situation is really hopeless, she doesn't think living is worthwhile, but then she thinks about her baby, who's still very young and needs his mother to help him find his feet in the world. This gives Jenna a reason to persist in her cause to fight cancer for a little longer. The boy gives her a hope, reason, strength and motivation to live.
2) Arthur, plays as a striker for a football club. His team are mid-way through their match with their local-rivals, and haven't scored a goal yet, they know if they don't win the game, their cup-run would be over, Arthur sees the look on his team-mates and the coach, they're all looking very glum. This invigorates Arthur, albeit paradoxically, to give in his best. He scores a goal and his team win the match. The look on the team-mates gave Arthur something to fight for.