“The doctrine of justification by faith alone does not imply that you are justified before God because you managed to work up enough faith in and by yourself to believe in Christ, which is impossible in the first place. Rather, the doctrine contrasts faith against works, emphasizing that we are justified by God through faith apart from works. This faith is itself not a work — that is, not a work of man, but a work of God in man.
Faith is a gift of God purchased by Christ for all those whom God has chosen for salvation. It is a gift even though it has been purchased by our Mediator because it is God who sovereignly decreed to save us through this Mediator in the first place. It is God who has sovereignly chosen those whom he would save by his grace through Christ, so that all of salvation is a gift of God — it is a sovereign gift of God, unmerited by man, that at the same time fully satisfies divine justice, since it has been merited by Christ. Thus salvation is from the grace of God alone, through the work of Christ alone, and by means of faith alone (that is, in contrast to works).
Therefore, when discussing the doctrine of justification by faith, we must not portray faith as a condition for salvation that God requires from us, as if we could produce faith in and of ourselves prior to regeneration and apart from the Spirit’s power. So, although it is correct to speak of faith as our necessary response to the gospel, this “response” of faith is in fact one of the very things that Christ’s atonement purchased for his elect, and that God bestows upon his chosen ones by his Spirit. In other words, God is the one who produces this response of faith in his elect.
When Scripture says that salvation is by faith and not by works, it is not throwing out works just to make faith a condition that man must fulfill in order to obtain salvation from God, although this is precisely how the doctrine is frequently but mistakenly portrayed, either by explicit statements or by implication. Faith is not a good work or a condition for salvation that God requires from us before he would do anything to save us; instead, God has already decreed and performed all that is necessary to secure the salvation of his chosen ones, and faith in the gospel is precisely one of those things that he has secured for the elect by the work of Christ, and that he sovereignly produces in their minds when he commands them to believe and summons them to himself by the gospel. There is therefore no place for boasting. Salvation comes from God through Christ alone. We cannot even boast about our faith, since it is a sovereign gift of God, merited by Christ for the elect.” – Vincent Cheung
