In this installment, Contarini unpacks the promise of God to which faith looks: the promise of forgiveness and of the justification of the ungodly (that is, when sinners are justified, they are justified as those who are themselves ungodly and wicked). The promise comes to those who believe in Christ.
How is this possible? Because God, when he saves a man, gives him the Spirit of Christ, by whom the benefits of Christ (including justification, sanctification, and adoption) are conveyed to him–but a man is not justified (in the sense in which he is using it here) 1 because of sanctification, adoption, etc., or because, e.g., he cries “Abba, Father,” or because of love shed abroad in his heart; for, according to Contarini, God also gives the redeemed “Christ Himself and all his justice,” or righteousness. This justice is given for free (that is, graciously), Contarini says, by imputation.
It is due to passages such as this that Francis Turretin can quote this treatise favorably in his Institutes of Elenctic Theology.
The promise of God, moreover, which it [i.e., faith] firmly believes–and for that reason conceives trust [fiduciam]–is (as blessed Thomas says in the First Part of the Second Part), that God remits sins and justifies the wicked through the mystery of Christ. For He Himself became the author of salvation for all those who believe in Him. 2 Therefore this motion of faith, after the renunciation of sin, raises the mind to God and turns [convertit] the soul [animum] to Him. When [the soul] has been turned, God, pouring his own Spirit [into it], heals, sanctifies, justifies, adopts it for a son through the Spirit of his own Son, through whom, when He has been poured into our hearts, we cry, “Abba, Father.” 3 In addition, he grants to us, together with the Spirit of Christ, Christ Himself; and all his justice–for free [gratis], out of his own mercy–he makes ours, he imputes [imputat] to us who have put on Christ. (De Iustificatione, pp. 590-1)