What might be the central idea of the passage above?

One possible central idea of the passage could be: God protects, provides for, and cares for those who call upon Him and put their trust in Him.  I hope that answers your question.

Based on the given sentence above, in this case, the word "they" should belong to a different line. This sentence can be paraphrase in these ways. 
"Because their words are not enough to create a spark." or you might phrase it this way too, "Because their words did not bring attention." Hope this answer helps you.