He is employing circular logic here. "Islam is true because Islam's holy texts prove it."
Know when to cut your losses, as people who are seriously programmed will outright reject even sound logic. Go for people who are on the fence instead.
As for most of his points, tell him that the ancient middle east was much more advanced than it is today, regardless of how good or bad the Quran is. This is because pagan religions focus on self-development, whereas Islam focuses primarily on one's devotion to an external entity. Just say this and don't continue more, as you will start to waste time.
Don't waste your time. You can't teach an insect to become a great scientist. You could spend this time helping yourself, or helping somebody who is actually capable of being helped like our people here.