Yet, I have to at least try and give an answer.
What is "The Divine Spark" The most likely explanation for this, I believe, would be that sudden spark of life. It is that sudden gift of life from the divine creator. In the context of the novel though, I believe that the divine spark is the dawning of a realization for a person. That sudden understanding that whatever it was that he was questioning in the past has, when he least expected it, finally found an answer.
The novel posed a serious question before me. After reading the passage in the book where the professor from the University of Virginia discussed his view of a Negro as a man with Chamberlain, I knew that I had a question to ask myself. Chamberlain said:
A Negro was not a man Why wasn't he to be considered as such Regardless of race and color, he lived, breathed, and existed in the same space as his landlord. I am of the opinion that this was said because, at the time a Negro was not human because he was unlearned. That was not entirely his fault as it was illegal to teach your slaves to read in some states during that time. There were still some whites during this period that could not read or write yet nobody ever thought that he was less of a man because of his illiteracy. Is being a man based on skin color No. That is shallow and totally unacceptable. To illustrate my point, these days, the Latin Americans living in the USA have taken the place of the Negroes. ...