For here is great misery, proud man! But there is greater mercy, a humble God! Take this love, therefore, as the end that is set before you, to which you are to refer all that you say, and, whatever you narrate, narrate it in such a manner that he to whom you are discoursing on hearing may believe, on believing may hope, on hoping may love.
Moreover, it is on the gound of that very severity of God, by which the hearts of mortals are agitated with a most wholesome terror, that love is to be built up; so that, rejoicing that he is loved by Him whom he fears, man may have boldness to love Him in return, and yet at the same time be afraid to displease His love toward himself, even should he be able to do so with impunity.
—St. Augustine, On Catechizing, par. 8 & 9.