Of this Scripture reminds us, lest, by believing that he was so created at first, we should ascribe to God what is most foreign to his nature. For this reason, Christ declares (John 8:44), that Satan, when he lies, “speaketh of his own,” and states the reason, “because he abode not in the truth.” By saying that he abode not in the truth, he certainly intimates that he once was in the truth, and by calling him the father of lies, he puts it out of his power to charge God with the depravity of which he was himself the cause.
