We often value the exterior and superficial aspect of things more than their inner reality. Bad manners taint everything even justice and reason. The 'how' of things matters most, and even the most disagreeable matters can be sweetened and gilded over with the proper appearance. Such is the bias and the weakness of the human mind.
The maxims of Christian life, which should draw upon the truths of the Gospel, are always partially symbolic of the mind and temperament of those who teach them to us. The former, by their natural sweetness, show us the quality of God's mercy; the latter, by their harshness, show us God's justice.
Just as there is no action weaker or more unreasonable than to submit one's judgment to another's, where there is no advantage to oneself, so also there is nothing greater or wiser than to place oneself unquestioningly under God's judgment by believing in every word He speaks.