"Scripture thus uses the term 'faith,' as the following sentence of Paul testifies, Romans 5:1: 'Being justified by faith, we have peace with God. Moreover, in this passage, to justify signifies, according to forensic usage, to acquit a guilty one and declare him righteous, but on account of the righteousness of another, namely, of Christ, which righteousness of another is communicated to us by faith...1 Corinthians 1:30. 2 Corinthians 5:21. But because the righteousness of Christ is given us by faith, faith is for this reason righteousness in us imputatively, i. e., it is that by which we are made acceptable to God on account of the imputation and ordinance of God, as Paul says, Romans 4:3, 5: Faith is reckoned as righteousness."
Apology of the Augsburg Confession, III. #184. Concordia Triglotta, St. Louis: Concordia Publishing House, 1921, p. 205f. Tappert, p. 154. Heiser, p. 60. Romans 5:1; 2 Corinthians 5:21; 1 Corinthians 1:30; Romans 4:3,5.