It's too bad you have a problem with the Holy Spirit convicting people to a saving knowledge of God through Warren's book.
And you know it because we have had a previous, lengthy discussion about it.
But...Please provide the Biblical basis/support for the Holy Spirit working through a man-written book to "convict people to a saving knowledge."
Faith comes by the hearing of the Word (not Warren's book)!
You moved the goalposts and changed the subject being addressed, which was how to test to see if something is correct and of God.
The test to be employed is comparison to Scripture. Your personal experience test is unbiblical.