Martin Lloyd Jones, Studies in the Sermon on the Mount (Eerdmans : 1960), pp. 129–30.
Go
Christian faith is essentially thinking. Look at the birds, think about them, and draw your deductions. Look at the grass, look at the lilies of the field, consider them. ... Faith, if you like, can be defined like this: It is a man insisting upon thinking when everything seems determined to bludgeon and knock him down in an intellectual sense. The trouble with the person of little faith is that, instead of controlling his own thought, his thought is being controlled by something else …