Even though synonyms generally share the same meaning, they might not apply in the same context. So, if you want to use one specific word you should do that instead of trying to find a synonym that doesn't quite fit into the context you've established. An example is if you want to use the sentence "I was mad", meaning "I was angry", you could look for a synonym. One synonym is "absurd". However, this is a different type of mad, meaning crazy instead of meaning angry. "I was absurd" has an entirely different meaning than originally intended. This is why you should always double check the contextual meaning of the synonym you want to use.
Dr. Brown shows Tita how phosphorous combined with oxygen can create a flame. He shares with her one of his grandmother’s old sayings that everyone has a box of matches inside them that can only be lit by oxygen and a candle. The oxygen, says Dr. Brown is a lover and the candle can be any other pleasure in life. He claims that finding the elements to ignite the matches within is a task that each person must complete in order to nourish his soul. If a person does not discover what ignites their matches then the matchbox dampens and the soul leaves the body in search of something to nourish it.
Also this symbol of “matches” repeats throughout the book as a symbol of Tita’s happiness and her life. When all the matches are light in the end she died.
https://www.gradesaver.com/like-water-for-chocolate/q-and-a/how-is-tita-like-a-book-of-matches-p115-116-422207