The Logical Chain of the Protestant Solas

Brad East argues that historical Protestant theological claims often overreach, giving as an example the assertion that the traditional five solas logically imply each other. “Any of them might be true—all of them might be true—but irrespective of that question, each principle requires independent demonstration; the solas are not necessarily a package deal.” I think Brad overstates things, and that the solas mostly imply each other as a package deal. A couple of thoughts on the outset before I make my friendly case. First, no magisterial Reformer or Reformed church ever distilled Protestant theology into the five solas or expressed them as a foundational unit. The arrangement of the five solas came centuries later in order to categorize a simplified essence of Protestant thought. Second, the definitions embedded in the terms matter. The solas are slogans, not dogmatic categories, and depending on the definitions used different conclusions are going to be reached about their logical necessitation.

Alright, so the foundational sola is Solus Christus, namely that Christ in his person and work alone sufficiently accomplished all that is necessary for salvation. This sola is not just that Christ is the single savior, but that who he is and what he did alone saves. The Reformers argued that we are justified by the person and work of Christ alone. That logically requires that no other person or activity justifies, saves, or contributes to that salvation in any way:

Christ in his person and work alone are what saves/justifies
Any other ground for salvation/justification is in addition to Christ’s work
∴ Salvation/justification is by Christ’s work (grace) alone

Sola Gratia is an expression of Solus Christus: Jesus saved by what he did, totally and truly. There is nothing in addition to who he is and what he is accomplished to which an appeal can be made for salvation. Sola Fide is also a corollary to Solus Christus. The Reformers all understood faith as something contrasted with works; faith is not a ground for salvation, nor is it a work by which a person is saved. The magisterial Reformers debated, and their heirs will continue to be debate, about whether faith is active or passive, when in the process of regeneration faith comes into play, and whether and in what way justification creates faith. But they uniformly understood faith as a not-a-work which is the instrument of reception of Christ. Could we conceive of a hypothetical world

“in which God wills to save by grace alone but not by faith alone. I don’t mean not-by-faith; I mean that, in such a world, God wills to save sinful human beings (just like us) using the instrumentality of faith but not solely the instrumentality of faith…God might save by faith through baptism, and both would be necessary for salvation, and both would remain utterly gratuitous means of grace, because neither would constitute a human work. Each would instead be a gift passively received, and on this schema, both would function together as God’s ordained means of saving grace.”

Yes, but not if we start off with Solus Christus. Part of my response here is an acknowledged form of special pleading: if we define faith as “not-a-work” then it meets the above criteria relating Christ’s work to salvation, while baptism or whatever else does not and could not. But that’s the point: the Reformers reasoned from the work of Christ to being justified by grace alone through faith alone by using these definitions. The solas came afterwards to explain.

Does salvation by grace alone necessarily imply that there even needs to be an instrument of salvation? Could we conceive of a world in which God justifies sinners without them turning to him in faith, i.e. using a different instrument for the giving of his grace which leaves the sinner saved yet unbelieving? Is there another not-a-work besides faith? The Reformers’ understanding of faith presupposes that humans are rationale, sentient, moral creatures who have turned away from God, who willingly disobey, doubt, and reject him, and therein stand condemned. That’s what it means to be a sinner rather than just defective. To be justified is the reversal of that condition, which requires there to be something descriptive of the sinner-turned-saint’s posture towards God that explains not only their status as righteous, but their obedience, trust, and embracing of God. That something is faith: belief in and resting upon the work of Christ for our salvation. Any other potential not-a-work instrument misses out on the necessity of belief for a justified human being; and any other instrument which is a work competes with Solus Christus as the warrant for salvation.

Sinful humans must receive God’s grace to be justified
Any means of receiving God’s grace besides faith would be a work, which is excluded by grace
∴ Salvation/justification is received by faith alone

Sola Gratia and Sola Fide are just expressions of Solus Christus. This is not a novel articulation, but Calvin’s argument in The Necessity of Reforming the Church, G.C. Berkouwer’s thoroughgoing thesis in Faith and Justification, and Anna Vind’s analysis about Luther’s own theological development in Martin Luther in Context.

Additionally, you could extend this chain to Soli Deo Gloria: if God saves sinners, not because of anything in them or any other external motivator (grace), but because of who he is, then the ultimate motivation and ends of salvation is God’s own self-originating pleasure (glory). God’s self-glory alone is the motivation and basis for salvation; or to flip it around, because we are saved by Christ alone by grace alone through faith alone, then there is no basis for boasting, but all the praise and attribution for salvation (glory) should be directed to God alone.

Brad’s post looks mainly at the relationship between Sola Gratia and Sola Fide on the one hand to Sola Scriptura on the other. This is where my defense of the logical necessitation is partial and I have sympathy for Brad’s rhetorical point that

“Imagine a world…in which God wills to save by grace alone…but simultaneously wills for his church to be led by successors to the apostles who, as a collective over time, are deputized by the Spirit of Christ to rule definitively (i.e., infallibly) on crucial questions of faith and morals, as and when conflicts arise over the interpretation of Scripture…The question, then, is not whether it is possible: It is possible, and it is absurd to doubt it.”

It’s true that the Reformers defined Sola Scriptura as something like “The Bible is the only infallible rule for faith and obedience”. If left at that, Brad is correct. However, that wasn’t the only dimension of Sola Scriptura the Reformers had in mind. Luther especially reasoned from the above logic connected to Sola Fide that there must be information relayed about the finished work of Christ so that the sinner would have something to believe in. That Christ-information must first proceed from God rather than humanity, or we’re back to square one when it comes to grace versus works; the gospel of justification is divine revelation received by faith, not something worked out by human reasoning. The Reformers’ conception of Sola Scriptura included the church as (fallible) messengers and interpreters of this revelation, but not as its source. This still does not logically necessitate the Bible as a written text, but Sola Scriptura also included the dimension “God alone is the self-revealer of salvation”. What is historically incidental is the commitment of that revelation to the written word, which the Reformers argued was an action of divine wisdom. The Westminster Confession of Faith literally opens up with the necessity of divine self-disclosure and the historical contingency of scripture.

Faith in Christ for salvation requires knowing Christ
The only way to know Christ apart from human work (grace) is by God’s self-revelation
∴ Faith is trusting in God’s self-revelation of Christ

If Sola Scriptura were renamed to something like Sola Revelatio Dei it would be a lot easier to see the causal link between Sola Fide and God’s word. But alas! the solas as slogans are here to stay. Yet while the solas as slogans may be retrospective, their substance was reasoned through by the Reformers from the starting point of the sufficiency of the person of Jesus.