Graeme Goldsworthy on the Four Reformation Solas
Grace alone is understood first of all in relation to the way salvation comes to us, and how we receive it. It is a principle that applies the notion of grace as the totally unmerited gift of God, whereby he acts for the good of those who deserve only his condemnation. It therefore rules out any sense that we can merit our salvation or contribute to it. Christ died for us while we were still helpless sinners (47).
Christ alone means that salvation is found nowhere else but in the person and work of Jesus Christ. This exclusivist conviction is based on the evidence of Scripture. Such evidence includes the specifically exclusivist claims concerning Jesus, and also the coherence of the biblical story. . . (48).
When the Reformers enunciated the principle of Scripture alone they asserted that there is no other source of truth available to us by which we can know Christ and, through him, God. Negatively, they repudiated the notion of a living tradition of the church as a separate source of truth that enjoys a similar authority to that of the Bible. They were not repudiating the role of tradition as such, but only seeking to subordinate it to the final authority of Scripture. It was not tradition that was the concern, but tradition that contradicted Scripture (48-49).
[Faith alone] is the truth expressed by Paul in Ephesians 2:8–9 that no human effort or good work can contribute to our salvation. Negatively, faith alone was a rejection of the whole Roman Catholic system of merits. It was a reversal of the upside-down gospel of Rome that put our subjective sanctification as the basis of justification. This had in effect opened the door to our works of sanctification being made the grounds of salvation (49).
Graeme Goldsworthy, Gospel-Centered Hermeneutics: Foundations and Principles of Evangelical Biblical Interpretation, (47-49).