I’m not inclined to read it, actually. Certainty is not an idol when you know who your father is, and your Father. Why should I be encouraged to doubt? It is nonsensical to me. It would be like encouraging a biological child to doubt who their real parents were, having grown up in a loving family for a decade and a half.
Certainly there may be a ‘dark night of the soul’ which may evoke questions such as “Where are you, Lord?”, and I may yet have such, not that I haven’t already to one degree or another, but when his presence has been so objectively revealed is his providential dealings with me in my septuagenarian life, “Is God real?”, “Do you exist?” and “Is Jesus who he says he is?” are not among them.
People who have not had a real encounter with the risen Lord would do well to pursue their doubts1 until they have one though (if they even want one). That is major understatement though, since it should be an imperative! The timing and placing of which is not something over which we any control, however… but we should still be seeking, even desperately (as was Maggie).
The account of Tim Keller’s parishioner that I so frequently cite is again relevant:
In God’s grace, some who don’t necessarily want one and who are not seeking (and who are maybe even fleeing The Hound of Heaven) may be given one unrequested. Phil Yancey’s conversion experience again comes to mind, and Augustine’s ←(a five minute podcast with transcript). It is interesting that co-instances are so frequently integral to Christians’ first experiences, right, Mi? 
:
Now, if you can give me compelling reasons why I should and also how to incite doubt…
1 From the blurb at Amazon, it looks like I might agree with Boyd on that.