Justification is by grace. That is, sinners do not deserve God’s favor.
Furthermore, justification is not on the basis of works (cf. Gal 2:15–16) but comes through faith (Rom 3:28).
Yet, in order to steer clear of ambiguity, theologians have taken time to identify the object of justifying faith. That is, what or who do we have faith in if we would be justified before God?
For the Reformed tradition, and according to the Bible, Christ alone is the object of justifying faith. God is therefore “just and the justifier of the one who has faith in Jesus” (Rom 3:26). That is, Christians are not saved by believing in belief, or having faith in faith, or trusting in trust. Instead, faith is the instrumental cause of our justification when and only when it is placed in Jesus Christ.
This call for explicit faith in Christ stood in contrast to the Scholastic notion of implicit faith (fides implicita). Catholicism taught that a person should simply believe the teachings of the Church, even if they do not understand the content of the teaching. The medieval theologian, John Brevicoxa (ca. 14th century), states the position clearly in his A Treatise on Faith, the Church, the Roman Pontiff, and the General Council. He writes, “to believe implicitly means firmly to assent to a universal truth from which many things follow and not to cling stubbornly to its negation.” Helpfully, Brevicoxa provides an illustration. He writes, “For anyone who believes that everything the Church asserts is true believes by implication the following statement: “Blessed Andrew was an Apostle of Christ,” since this has been handed down by the Church. He believes this even though he does not know the Church makes such an assertion” (italics added). There was, then, an idea in Roman Catholic theology that faith did not necessarily and explicitly fall on Jesus. It was sufficient to assent to the teachings of the Catholic Church, regardless of whether or not you knew what the Church taught explicitly.
John Calvin asks in response to such a notion, “Is this what believing means—to understand nothing, provided only that you submit your feeling obediently to the church?” Calvin demurs. True faith does not mean turning over to the church “the task of inquiring and knowing…” Rather, “faith rests not on ignorance, but on knowledge.” According to Calvin, then, the implicit faith of Roman theology does not necessarily entail understanding or seeking to understand. Given Calvin’s definition of faith as knowledge (see Institutes 3.2.7), this obviously will not hold. Therefore, implicit faith is “fiction” and “not only buries true faith, but utterly destroys it.” Again, “Faith consists in the knowledge of God and Christ (John 17:3), not in reverence for the church.”
What we find is Calvin playing the part of a cultural critic as he responds to a contemporary theological debate. For Calvin, the object of saving faith is Jesus Christ. We cannot seek the Father apart from the Son. Simply assenting to the teachings of the Catholic Church, without understanding what they teach, is not saving faith (cf. 2 Tim. 3:7)
What we find in Calvin concerning the object of faith is reiterated time and again in his theological heirs. For instance, John Owen devotes a substantial section to the object of justifying faith. Owen states repeatedly that Jesus Christ is “the adequate and proper object of justifying faith.” According to Owen, in the Bible, God the Father is sometimes said to be the object of faith (e.g. John 5:24), as are the promises of God (e.g. Acts 2:39; Rom 4:16). Yet, Owen maintains that Christ is the final or proper object. The Father is the object in so much as he sends the Son; the promises are the object as they point to Messiah Jesus. Thus, Owen concludes:
Wherefore asserting that Lord Jesus Christ in the work of his mediation to be the object of faith to justification, I include therein the grace of God which is the cause, the pardon of sin which is the effect, and the promises of the gospel which are the means, of communicating Christ and the benefit of his mediation to us.
The Westminster Confession of Faith (WCF) states the Reformed position plainly. “Faith, thus receiving and resting on Christ and his righteousness, is the alone instrument of justification.” Note carefully what or who faith rests on. Justifying faith rests or terminates “on Christ and his righteousness.” The reason this is important is that it is Christ alone who provides the benefits we need in order to be saved on the final day. Christ is the necessary object of faith because it is only Jesus who has paid our sin debt and only Christ who has lived a perfectly righteous life.
In short, Jesus Christ is the object of saving faith. By faith, we take hold of Christ and all his saving benefits. In Christ, we find that our debt has been paid (Col 2:14). Furthermore, through faith in Jesus, we find his righteousness is our righteousness, not inherently but by imputation. “For his sake I have suffered the loss of all things and count them as rubbish, in order that I may gain Christ and be found in him, not having a righteousness of my own that comes from the law, but that which comes through faith in Christ, the righteousness from God that depends on faith” (Phil 2:8–9). Thus, we look to Jesus as the object of our faith in order to be justified in God’s sight.
 Yet, even here there is some debate over key texts and whether or not certain passages should be translated with a subjective or objective understanding of the genitive. For a discussion of the debate over “faith in Christ” or the “faithfulness of Christ,” see Schreiner, Justification by Faith, 124–132. As Schreiner notes, however, apart from the debated texts in this particular discussion, there are clear texts where Christ is the clear object of justifying faith (Eph 1:15; Col 1:4; 2:5; 2 Tim 3:15; Philm 5).
 Heiko Augustinus Oberman, Forerunners of the Reformation: The Shape of Late Medieval Thought, 1st Fortress Press ed. (Philadelphia, PA: Fortress Press, 1981), 69.
 William Ockham writes, “For whatever the Roman Catholic Church explicitly or implicitly believes, this and nothing else either explicitly or implicitly I believe” (quoted by McNeil in Calvin, Institutes, 545).
 Calvin, Institutes, 545.
 Ibid. Calvin does not deny that there are levels of implicit faith as we live with imperfect knowledge during the present age. Yet, he does deny that those who merely believe implicitly, believe savingly (Calvin, 545).
 Owen, The Doctrine of Justification by Faith, 97–98.
 Ibid., 99.
 Sproul, Truths We Confess, 256