Simplest: faith justifies because it is imputed to the believer for righteousness
Simplest: faith justifies because it is imputed to the believer for righteousness (Rom 4).
God counts the living believer just for Christ's death and obedience.
Latin
XXII. Simplicissimum nobis videtur si dicamus, fidem justificare, quia credenti, sua fides imputatur ad justitiam. Sic enim Apostolus ipse mentem suam explicat, de justificatione per fidem ex professo agens, Rom. 4. Credenti, inquit, in eum qui justificat impium, reputatur fides ejus ad justitiam. Et in hunc finem citat illud Mosis, Credidit Abraham Deo, & reputatum est ei ad justitiam. Fides autem ad justitiam imputari dicitur, quia Deus illum qui viva fide in Christum credit pro justo habet & reputat, eum a poena peccati liberans, & ad vitam aeternam acceptans, propter Christi mortem & obedientiam.