"the depth of our doubt is roughly proportional to the depth of our faith"

"...Perhaps that's a general principle: The depth of our doubt is roughly proportional to the depth of our faith. Those with strong faith have equally strong doubts. That principle bears out in the other direction as well: People with a trivial and shallow faith usually have trivial and shallow doubts. And if you ask them, Who is this god you doubt? you'll likely find this: He's safe.” -Mark Buchanan, Your God is Too Safe, pp 67-68.