Originally posted as a part of a longer article at deepsouthreformation.com

There’s hardly a more relevant question in the Christian life than that of assurance of salvation. Peter affirms that the goal of our faith is salvation, (1 Pet. 1:9) so the stakes are pretty high. Yet for a question of such ultimate importance, it’s hardly ever asked. In the church today, there are often more assumptions than answers. And that can be dangerous. In reality, the simple question “How do I know I’m saved?” seems to be one of the best indications that someone takes their faith, and thus their salvation, seriously. So let’s be serious for a moment. How do we know? Can we know? Let’s go back to the first Protestant. To a man plagued with the question of assurance.

It could be said that the entire Protestant Reformation was an issue over assurance. Much of the Reformers’ critique of the old church was leveled precisely against those features of the Roman Catholic system that left people doubtful and anxious about their salvation. This is why Martin Luther deemed the doctrine of justification by faith “the central article of our teaching.” It helped him to reconcile the obvious tension between God’s holiness and persistent human sinfulness. For Luther, theology wasn’t an exercise in scholasticism. It was a life-and-death matter. His extremely tender conscience couldn’t bear the weight of God’s impending judgment, nor could it find sufficient assurance in the Catholic system of penance and priestly absolution. The system of indulgences not only failed to engender the necessary repentance that came with sincere faith, but it also left the sinner without any real spiritual security. Was God up there? Was he pleased? Was he angry? The troubled young Luther was plagued with such a sense of panic under God’s wrath that eventually his supervising monk, Johann von Staupitz, ordered him to stop concocting sins in his head! Luther had too many transgressions to confess! This sense of foreboding dread and despair was what Luther called Anfechtung, a sense of doom before God’s watchful eye: “I did not learn my theology all at once, but I had to search deeper for it, where my temptations took me…Not understanding, reading, or speculation, but living, nay, rather dying and being damned make a theologian.” Here in his anxiety-ridden state, Luther found the mercy of a God who was both “just and the justifier of the one who has faith in Jesus.” (Rom. 3:26) What abbots and bishops could not furnish for Martin Luther, Christ could. Because of assurance, young Luther became disillusioned with the fabricated religion of Rome: “No man can be assured of his salvation by any episcopal function…because the Apostle (Paul) orders us to work out our salvation constantly in fear and trembling.” Luther continued, “the first and only duty of the bishops, however, is to see that people learn the gospel and the love of Christ.” Therefore, to be Protestant, to some degree, is to be certain of one’s salvation. But as we’ll see, that hard-fought assurance became more difficult to define.

Luther’s discovery of assurance and subsequent break with Rome coincided with his new understanding of the ‘justice of God’ in Romans 1:17. For years, the word righteousness had struck fear into the heart of the sinful Augustinian monk. The ‘righteousness’ of God was a divine attribute that Luther dreaded, as he knew himself to be wholly unrighteous, and worthy of a righteous punishment. Luther’s conversion, however, came with his eventual re-interpretation of Romans 1:17: the ‘righteousness of God’ was, in fact, an “alien righteousness” given to sinners. “For He, Himself is our sole righteousness until we are conformed to His likeness.” Christ had satisfied the righteousness of God by supplying His own to sinners. [Sentence Removed] Justification was a legal action performed by Christ on behalf of the sinner, not worked from within, but declared from without. This is how sinners could remain sinful and have certainty that they were indeed saved. Christians were “simul justus et peccator”: simultaneously just and sinner. Thus the Protestant doctrine of assurance was born. To have faith in Christ is not to achieve salvation personally, but to personally accept Christ’s salvific work done on our behalf. To Luther and to all of his spiritual offspring, Christ Himself is the assurance of sinners. Unlike Roman Catholicism that teaches that grace must be conferred and infused via physical sacraments, Protestants boast in the finished work of Christ via faith. And the result isn’t infused righteousness, but imputed righteousness! We receive the credit for the perfect life of Christ.