10 Whosoever doeth not righteousness. To do righteousness and to do sin, are here set in opposition the one to the other. Then, to do righteousness is no other thing than to fear God from the heart, and to walk in his commandments as far as human weakness will permit; for though righteousness in a strict sense is a perfect keeping of the law, from which the faithful are always far off; yet as offenses and fallings are not imputed to them by God, righteousness is that imperfect obedience which they render to him. But John declares that all who do not live righteously are not of God, because all those whom God calls, he regenerates by his Spirit. Hence newness of life is a perpetual evidence of divine adoption.

Neither he who loveth not his brother. He accommodates a general doctrine to his own purpose. For hitherto he has been exhorting the faithful to brotherly love; now, for the same end, he refers to true righteousness. Hence this clause is added instead of an explanation. But I have already stated the reason why the whole of righteousness is included in brotherly love. The love of God holds, indeed, the first place; but as on it depends love towards men, it is often, as a part for the whole, comprehended under it, and also the latter under the former. Then he declares that every one who is endued with benevolence and humanity, is thus just, and is to be so deemed, because love is rite fulfillment of the law. He confirms this declaration by saying that the faithful had been so taught from the beginning; for by these words he intimates that the statement which he made ought not to have appeared new to them.

12 Not as Cain This is another confirmation, taken from what is contrary; for in the reprobate and the children of the devil hatred reigns, and it holds, as it were, the chief place in their life; and he brings forward Cain as an instance. It served in the meantime to give them consolation, as he at length concluded by saying, Marvel not, if the world hate you.

This explanation ought to be carefully noticed, for men ever blunder as to the way of living, because they make holiness to consist of fictitious works, and while they torment themselves with trifles, they think themselves doubly acceptable to God, as the monks, who proudly call their mode of living a state of perfection; nor is there any other worship of God under the Papacy but a mass of superstitions. But the Apostle testifies that this righteousness alone is approved by God, that is, if we love one another; and further, that the devil reigns where hatred, dissimulation, envy, and enmity prevail. We ought, however, at the same time, to bear in mind what I have already touched upon, that brotherly love, as it proceeds from the love of God as an effect from a cause, is not disjoined from it, but on the contrary is commended by John on this account, because it is an evidence of our love to God.

By saying that Cain was driven to slay his brother, because his works were evil, he intimates what I have already stated, that when impiety rules, hatred occupies the first place. He refers to Abel’s righteous works, that we may learn to endure patiently when the world hates us gratuitously, without any just provocation.