In Reformed theology, the noun salvation is typically used in two ways. Sometimes it is used as a synonym for justification. When used this way, it does not include sanctification, since, according to the Reformed confession, justification is a declarative act of God whereby he credits (imputes) to sinners the perfect, active and suffering righteousness of Christ so that it is as if those sinners to whom Christ’s righteousness has been so imputed are considered to have themselves accomplished personally all that Christ did for them as their substitute. Further, we say that this benefit is received through faith alone (sola fide), defined as trusting, resting in and receiving Christ and his righteousness. We confess that both the imputation of Christ’s righteousness and faith as the receiving instrument are nothing but God’s free gifts. Hence we attribute all of this to God’s favour (grace) alone. The slogan for this is sola gratia, by grace alone.
We also say, however, that God’s grace is twofold (duplex). Justification is the first benefit (beneficium) and sanctification is the second. It is not a “second blessing” in the way neo-Pentecostalists speak of tongues, etc as a “second blessing”, as if there are two classes of Christians, those with and those without. Rather, we say that progressive sanctification flows from or grows out of and is grounded in our justification. It too is a gift of God; his work in us by his Spirit, through his divinely ordained means, whereby he puts to death the sin in us and makes us alive in Christ, whereby he is gradually and graciously conforming us to Christ.
The noun salvation is also used to describe that whole complex of benefits, justification and sanctification. In this sense we are thinking both of deliverance from the wrath to come and from the effects of the fall in this life. In our confessional documents and our theology both of these benefits (justification and sanctification) are said to be by grace alone. Often, though not perhaps universally, in our theology (as distinct from our ecclesiastical confessions) salvation is said to be through faith alone. That is, the sole instrument of justification and salvation is faith alone. In our confessions certainly and in our better writers, good works are said to be a necessary concomitant or an accompanying fruit and evidence of justification and salvation. Read the full article by R. Scott Clark.