Given the controversies surrounding justification in his day, it's no surprise that Calvin camps out on Gen. 15.6 ("[Abraham] believed the Lord, and he counted it to him as righteousness") for a significant space of time in his commentary on the first book of the Bible. This text, after all, figures critically in Paul's defense of justification by faith (alone) in both Romans and Galatians (cp. Rom. 3.21-4.25 & Gal. 3.1-9). Operating (like Paul) on the principle that "what is... related concerning [Abraham]" in Gen. 15 "is applicable to all," Calvin reflects at length on the nature and named fruit of Abraham's faith in God's repeat promise of a spiritual seed/Seed and a heavenly inheritance (Gen. 15.1-5; cf. Gal. 3.16).
More surprising, albeit limited, is what the Reformer says in this context about Abraham's (and thus our own) doubt in relation to God's promise. No matter its ultimate theological import, Calvin reads Gen. 15.6 in its immediate context, and consequently notes the rather remarkable expression of Abraham's uncertainty regarding God's purposes for him that occurs just two verses after we read of Abraham's faith and its justifying fruit. When God reiterates, in Gen. 15.7, the promise of a (heavenly) land for Abraham and his (spiritual) children (the very promise Abraham has just believed), Abraham responds, in Gen. 15.8, with a question which suggests something other than complete confidence in God's ability and/or purpose to deliver on the same: "Lord God, how am I to know that I will possess [this]?"
One might expect Calvin to censure Abraham for this apparent instance of doubt regarding God's promise. In fact, however, he is rather forgiving of the Patriarch. The grace he extends to Abraham stems in part from the observation that "the protracted delay" between God's promise and its fulfillment "was no small obstacle to Abram's faith." It stems, I think, in equal part from the observation that every true believer who lives between the promise of eternal reward and its fulfillment is, like Abraham, plagued at times by some uncertainty about the things for which he has come to hope and/or the purpose of the One who promises those things.
In his treatment of Abraham's faith, Calvin goes out of his way to insist that good works are antithetical to genuine belief (in the context of justification). This follows from "the mutual relation between the free promise and faith." Insofar as forgiveness and restoration from sin are freely offered to sinners on the basis of the promised Seed's person and work, efforts to earn forgiveness and restoration constitute insults of the highest order. Only the worst kind of ingrate, after all, responds to the receipt of a birthday present by pulling out his wallet and insisting upon paying the giver for the gift.
But doubt, unlike good works, can apparently coincide with genuine belief. Indeed, doubt can point to the existence of true faith: "[Abraham's] questioning with God is rather a proof of faith than a sign of incredulity." Calvin explains: "The Lord... concedes to his children that they may freely express any objection which comes into their mind. For he does not act so strictly with them as not to suffer himself to be questioned. Yea, the more certainly Abram was persuaded that God was true, and the more he was attached to His word, so much the more familiarly did he disburden his cares into God's bosom." Of course, such an assumption (or rather, conviction) frees believers to deal with doubt exactly as Abraham did: taking it directly to God in prayer.
Calvin's comments on doubt in relation to faith and God's promise are heavily informed, I suggest, by the Reformer's characteristic sensitivity to the tender, fatherly nature of God's relationship to believers. After all, a kind father (such as God truly is) who has guaranteed some good (say, a trip to the sea) to his children doesn't reprimand them for unbelief when they pester him with questions about whether and when he will deliver on his promise. Indeed, such pestering is proof that his children nourish a proper expectation and hope for the joy held out before them. The absence of such pestering would point to a conviction that the promise itself was vapid, or to indifference towards the good promised, sentiments opposed to faith and hope respectively.
If there is solace to be found in Calvin's conviction, drawing on Abraham's example, that true (justifying) faith leaves room for doubt, there is equal solace to be found in his observations regarding God's response to Abraham's uncertainty. God does one better than reassure Abraham (or us) with a further word of promise, as thoroughly sufficient as such a word should be. God answers Abraham's doubt regarding his covenant word with a covenant ritual, a veritable feast for Abraham's senses in which God essentially pledges himself to Self-destruction should he fail to deliver on his promise (Gen. 15.9-21).
God's response to Abraham's doubt is every bit as paradigmatic for present-day believers' experience as Abraham's faith and doubt as such. "For the Lord, in order more deeply to affect his own people, and more efficaciously penetrate their minds, after he has reached their ears by his word, also arrests their eyes by external symbols, that eyes and ears may consent together." The rituals by which God confirms his word of promise to us (namely, baptism and the Lord's Supper) may, upon the surface, seem as strange and irrelevant to our doubts as God's solution to Abraham's doubt first (perhaps) did to the Patriarch. It's unlikely, after all, that Abraham immediately felt his anxieties regarding God's purpose for him resolved when God, in response to his questioning, told him to gather a cow, a goat, ram, and two birds (Gen. 15.9). But if, like Abraham, we wait and see how God employs such "external symbols" to confirm his promise to us, we stand to gain substantial (divine) medicine for our doubt. Thus the sacraments, which both symbolize and secure/enlarge our union with Christ, our designed by God to resolve our anxieties and bolster our confidence that we will one day possess in full the fruit of our union with Christ, which is nothing less than eternal fellowship with God himself. "Let us therefore learn meekly to embrace those helps which God offers for the confirmation of our faith."
Aaron Clay Denlinger is professor of church history and historical theology at Reformation Bible College in Sanford, Florida.