Every believer exists in a permanent tension that cannot be resolved this side of glory: simul justus et peccator — simultaneously righteous and a sinner. Before God (coram Deo), the Christian is declared fully righteous — not partially, not progressively, but completely — through union with Christ and the imputation of His righteousness. In that same moment, considered in himself (coram hominibus), the believer is still a sinner — genuinely, not merely legally. The "old man" is dying but not yet dead. The flesh still wars against the Spirit. Paul's anguish in Romans 7 ("I do what I do not want") is not the voice of a pre-Christian but of a mature apostle describing the actual interior life of the regenerate soul. This phrase guards against two errors: (1) presuming that justification removes the reality of remaining sin — it does not, and believers who pretend otherwise are liars (1 John 1:8); (2) concluding that remaining sin cancels or threatens justification — it does not, because justification rests on Christ's record, not the believer's performance. The Christian stands fully acquitted and is still being renewed. Both are true, fully and simultaneously.
JUSTIFIED — (Webster 1828) Freed from guilt or sin; pardoned; absolved; treated as righteous. In theology, freed from the guilt of sin in the sight of God; accepted as righteous through the merits of Christ imputed to the believer.
SINNER — (Webster 1828) One that has voluntarily violated the divine law; a transgressor of the divine commands; one that has done wrong, or that is destitute of holiness; one that sins habitually.
Note: Webster did not combine these into a formal phrase, but the tension between them — that the pardoned man is still one who sins — is thoroughly embedded in the Reformed and Lutheran traditions Webster inhabited.
Modern evangelicalism corrupts this teaching in two directions simultaneously. On one side, the "let go and let God" brand of sanctification teaches a higher-life theology in which the believer can move beyond the simul — achieving a state of near-sinlessness through full surrender. This is flatly contradicted by 1 John 1:8 and the lived experience of every honest Christian. On the other side, antinomian versions of grace theology use the simul as a permanent license — "I'm just a sinner saved by grace" becomes a reason not to pursue holiness, as though the "peccator" half of the equation has swallowed the "justus." Luther never meant that. The simul describes what is true about believers while they are being renewed — it is not a ceiling on sanctification. The goal is still to be transformed into the image of Christ (Romans 8:29). The tension is real; it is not an excuse.
• Romans 7:24–25 — "Wretched man that I am! Who will deliver me from this body of death? Thanks be to God through Jesus Christ our Lord!"
• 1 John 1:8 — "If we say we have no sin, we deceive ourselves, and the truth is not in us."
• Romans 5:1 — "Therefore, since we have been justified by faith, we have peace with God through our Lord Jesus Christ."
• Galatians 5:17 — "The desires of the flesh are against the Spirit, and the desires of the Spirit are against the flesh, for these are opposed to each other."
• Romans 8:1 — "There is therefore now no condemnation for those who are in Christ Jesus."
• The simul guards against spiritual pride: no matter how mature the saint, they have not graduated beyond needing the gospel, the cross, and the daily forgiveness of sins.
• It also guards against despair: the believer who falls into sin has not lost their standing before God, because that standing was never based on their own performance.
• Luther said Christians need to hear the gospel every day, precisely because every day they wake up as peccatores who need to be re-declared justi — not re-justified, but freshly reminded of what is already true.