There’s a reason we wait until dark to light fireworks. Against the dark skies, the glow of the explosions is brightest. Fireworks during the day, like at a baseball game, are loud but not nearly as interesting to observe.

The same could be said in the realm of ideas; doctrines, principles, and philosophies always have heightened clarity when put in the context of competing concepts.

For example, the good news of the gospel – the perfect life, substitutionary death, and validating resurrection of Christ for sinners – becomes crystal clear against the backdrop of the bad news of our sin and deserved judgment.

This principle has again become pertinent to me recently as I studied theological ideas around the justification of sinners and the assurance of their salvation.

Both the Westminster Confession of Faith (1646) and the London Baptist Confession of Faith (1687) have nearly identical sections entitled, Of the Assurance of Grace and Salvation. They are both contained in Chapters 18 of their respective documents.

In the first paragraph of these chapters, both Confessions have this identical statement: “Such as truly believe in the Lord Jesus, and love him in sincerity, endeavoring to walk in all good conscience before him, may, in this life, be certainly assured that they are in the state of grace, and may rejoice in the hope of the glory of God, which hope shall never make them ashamed.”

What a powerful statement! True believers “may be certainly assured that they are in the state of grace.”

Now, I have taken hope and comfort from Scripture passages like the entire book of 1 John, which was specifically written to assure believers of their standing in Christ. “I write these things to you who believe in the name of the Son of God, that you may know that you have eternal life” (1 John 5:13). I have pursued godly dispositions and holy affections as I endeavor to confirm my calling and election (2 Peter 1:10). When doubts assail, I have examined myself to see whether I am in the faith (2 Cor. 13:5).

All of these verses (and many others) support the idea that we can, in this life, know we are saved, in the state of grace, rejoicing in hope (Rom. 5:2).

It is on the basis of Scriptures like these that the Confessions make their affirmations of the reality of assurance for the believer.

While our election, calling, and justification are sure, our feelings and awareness of assurance can wax and wane. This is why we must pursue it.

First, we base our assurance objectively on the promises of God in his Holy Word, which never fail.

Additionally, we base our assurance subjectively on our experience as we see the fruits of justification at work and increasing in our lives.

“For if these qualities are yours and are increasing, they keep you from being ineffective or unfruitful in the knowledge of our Lord Jesus Christ. For whoever lacks these qualities is so nearsighted that he is blind, having forgotten that he was cleansed from his former sins. Therefore, brothers, be all the more diligent to confirm your calling and election, for if you practice these qualities you will never fall. For in this way there will be richly provided for you an entrance into the eternal kingdom of our Lord and Savior Jesus Christ.”

2 Peter 1:8-11

The Synod of Dort (1619) had this to say regarding assurance: “The elect in due time, though in various degrees and in different measures, attain the assurance of this their eternal and unchangeable election,…by observing in themselves, with a spiritual joy and holy pleasure, the infallible fruits of election pointed out in the Word of God – such as a true faith in Christ, filial fear, a godly sorrow for sin, a hungering and thirsting after righteousness, etc.” (First Head, Article 12).

So then, we are told Scripturally that we can know that we have eternal life, and we are to pursue this assurance and certainty with all godly vigor. That in itself is a powerful and comforting truth.

Now, for some context…

To give even more clarity to this truth, let’s now consider the historical and theological backdrop.

These Confessional statements were written in the early decades of the Protestant Reformation. They come in stark contrast to Roman Catholic dogma, which was reaffirmed at the Council of Trent (1545-1563).

At the center of the teaching on assurance is the biblical concept that justification is a legal declaration of complete acquittal of sins. Through the finished work of Christ, we are declared and treated as righteous through faith. In Protestant theology, justification is a completed state, by which we are forgiven and accepted by God.

This is the foundation of assurance.

However, in Roman Catholic teaching, even though terms like grace, faith, and justification are used, they do not mean the same thing. In Catholic teaching, justification is not declaring someone righteous, but making someone righteous. “Justification is not only the remission of sins, but sanctification and renovation of the interior man…whereby a man becomes just instead of unjust” (Trent, Chapter 7). Since justification includes sanctification which is not final at any point in life, a consistent Catholic would not say that they are justified, but that at the end of their days, they hope to be.

Consequently, if a person cannot say with certainty that they are now justified, they cannot claim to have assurance of salvation. In fact, it’s not just that assurance is impossible; it is not to be pursued at all! Trent calls assurance as I have described it, “a vain and ungodly confidence.” “If anyone says that he will for certain, with an absolute and infallible certainty, have that great gift of perseverance even to the end, unless he shall have learned this by a special revelation, let him be anathema” (Trent, Canon 16).

So then, those who penned the Reformed Confessions were not simply espousing the biblical truth on assurance as Scripture teaches it; they were doing so against a backdrop of despair and vain hope of the Roman Catholic faith rooted in works righteousness.

Truly, the motto of the Reformation stands, Post Tenebras Lux (After darkness, light)! What a great fireworks display this truth is.