That’s a Fair point. If I may offer a defense on Sproul’s behalf though. This is a short clip from a longer lecture, so maybe more context would add clarity? Also, his target audience here is believers - i.e. those who have come to trust in God. He is encouraging them to grow in their knowledge of the faith as the writers of scripture do. A different audience might respond in a way that was not intended. Is the preacher ultimately able to control and be responsible for people’s response to their message anyway?

Just a thought I wanted to add as well. While questioning/doubting God shows a lack of faith, I think the Lord is compassionate to such failure and very patient with it. He uses it as an opportunity to grow. I’m thinking of the example of Habbakkuk who questioned God and the Lord graciously answered. Job also. Perhaps most of all, we see the Lord’s disciples asking many questions. Sometimes, he has to rebuke them for their lack of faith, spiritual ignornance, and pride. But he is very patient in his teaching them.