#49 Art. IV “Justification” of the Apology of the Augsburg Confession.These things cannot take place, before we are justified by faith and born anew through the Holy Spirit ; because, in the first place, no one can keep the law, without the knowledge of Christ, nor can any one fulfil the law, without the Holy Spirit. But we cannot receive the Holy Ghost, except through faith, as Paul says to the Galatians 3:14 : “That we might receive the promise of the Spirit through faith.”
It is, moreover, impossible for the human heart to love God by the agency of the law or works alone. The law manifests nothing but the wrath and severity of God, it accuses us, and shows how fearfully he will chastise sin with punishments both temporal and eternal. Hence, what the scholastics teach concerning the love of God, is a wild conceit ; it being impossible to love God, before we know and embrace his mercy through faith. Then only does God become (objectum amabile) object amiable, lovely.
Although reason may, to some extent enable us, by its innate light, to lead an honest life, and to perform the external works of the law, without Christ and the Holy Spirit, yet it is true, as we stated above, the principal parts of the divine law, that is, turning the whole heart to God, and reverencing him sincerely, (as required in the first table, and in the first and highest commandment,) cannot be kept without the Holy Spirit. (Henkel Translation, p. 180-181).