Is it possible to ask questions when contemplating the Quran, such as asking about the relationship between His saying, the Most High, "Our Lord encompasses all things in knowledge," and reverting to disbelief? And can the answers be used in an authored book?

The relationship between the verse: "Our Lord encompasses all things in knowledge" and reverting to the path of disbelief is that this phrase signifies delegation and submission to Allah, to His wisdom and His complete knowledge. Consequently, they do not feel safe from His plan, because they have not encompassed His knowledge, and He alone is the All-Knower of everything. And His saying, "unless our Lord, Allah, wills" and "Our Lord encompasses all things in knowledge" indicates not feeling safe from Allah's plan and turning entirely to Him. This is confirmed by His saying, "In Allah have we put our trust," which is an expression of helplessness and reliance upon Him, glorified be He.