To which I say, what?
Now, to be fair, I'm sure this does actually happen in real life at times. I'm sure there are places where people are that ignorant, or that lacking in confidence about the integrity of their beliefs, that honest questions and doubts frighten them and they try to silence the questioner as soon as possible. So I'm not saying this scenario is implausible, as such.
That being said, I have spent my whole life attending conservative evangelical Christian churches, and I have NEVER heard anyone say anything like this. Not from the pulpit, not in small Bible studies, not in personal conversation. What I've always heard instead is that the Christian faith is reasonable and that there is good evidence for believing it, and that people who are struggling with doubts and questions need more information, not less.
In my experience, the most likely scenario is that the doubting person will be referred to a preacher or elder or other spiritual counselor to discuss the issues that are causing them doubt and confusion. The counselor would then do a Bible study with the doubting person to help them see what the Bible really says about those troublesome issues, and would probably also suggest some books which give historical, philosophical, logical and scientific evidences for the integrity of the Christian faith.
All of which is not to say that the doubting person will necessarily respond to that counseling, or that they won't still turn their back on their faith at the end of it. They may decide that the evidence offered to them is unsatisfying and/or that their feelings of dissatisfaction are too strong to allow them to continue as a practicing Christian (or at least in that particular church). But will they be able to say that they were told, "Reason has nothing to do with faith, so just shut up and believe"? Not in my experience. In fact, I'd say that would be proof that something was very badly wrong with that church and no one of integrity or good conscience should be associated with it anyway.
When John the Baptist was in prison and began to doubt that Jesus was the Messiah (and the gospels tell us quite clearly that he did), Jesus didn't say, "Tell John I'm disappointed in him for his lack of faith." He didn't even say, "Tell John to remember what he saw with his own eyes when he baptized Me -- how the Spirit of God came down from heaven like a dove and the Father Himself declared that He was well pleased with Me." Instead, He performed a number of new miracles in the sight of John's disciples, and he said, "Go back and tell John what you have just seen -- how I have healed these people before your eyes. Blessed is the man who does not fall away on account of me."
And then, instead of launching into a sermon on the evils of doubt using John as an example, Jesus turned to the crowds and began to talk about how great a prophet John was. He did not say one word of reproach against John for struggling with doubt. Instead, He gave John the encouragement -- and evidence -- that he needed to regain his confidence and hope.
That is a Biblical, Christian response to doubt.
Of course, if your whole point is to write a book about how Christianity is weak and unsatisfying and poisonous to the intellect, and how much happier you will be if you abandon it in favor of some other belief (because goodness knows people of other religions and philosophies never ever struggle with doubt or dissatisfaction about those beliefs, and it's not like self-questioning and uncertainty is endemic to mankind or anything) then I guess there's not going to be much room in the book to include things like counseling and apologetics, or any Christian characters who actually possess some degree of intellect, education and integrity.
But if you write a book like that, then I reserve the right to roll my eyes at your bigotry and walk away.