It’s this book:
Tim Challies explains:
If you struggle believing what the Bible says, but learn to find security in the testimony of a toddler, well, I feel sorry for you. And I do not mean this in a condescending way. If God’s Word is not sufficient for you, if the testimony of his Spirit, given to believers, is not enough for you, you will not find any true hope in the unproven tales of a child. This hope may last for a moment, but it will not sustain you, it will not bless you, in those times when hope is waning and times are hard.
So reject this book. Do not read it. Do not believe it. And do not feel guilty doing so.
Read his whole review here.