City of God

Moreover, as if we had been inquiring why the devil did not abide in the truth, our Lord subjoins the reason, saying, “because the truth is not in him.” Now, it would be in him had he abode in it. But the phraseology is unusual. For, as the words stand, “He abode not in the truth, because the truth is not in him,” it seems as if the truth's not being in him were the cause of his not abiding in it; whereas his not abiding in the truth is rather the cause of its not being in him. The same form of speech is found in the psalm: “I have called upon You, for You have heard me, O God,” where we should expect it to be said, You have heard me, O God, for I have called upon You. But when he had said, “I have called,” then, as if some one were seeking proof of this, he demonstrates the effectual earnestness of his prayer by the effect of God's hearing it; as if he had said, The proof that I have prayed is that You have heard me.