"If faith carries within itself so much movement and struggle, it is not surprising ...

if faith and doubt set themselves against each other, and if the soul is set in a painful dilemma." Eucken considers it to be an inevitable, and indeed a necessary accompaniment of religious experience, and his own words on the point are forcible and clear.
"Doubt ...

does not appear as something monstrous and atrocious, though it would appear so if a perfect circle of ideas presented itself to man and demanded his assent as a bounden duty.

For where it is necessary to lay hold on a new life, and to bring to consummation an inward transformation, then a personal experience and testing are needed.

But no proof is definite which clings from the beginning to the final result, and places on one side all possibility of an antithesis.