The Protestant Reformer, Martin Luther, coined the Latin phrase simul iustus et peccator, which translates as, simultaneously righteous and a sinner. Luther correctly understood the biblical teaching that we are righteous in God’s sight because of the righteousness of Christ imputed to us at salvation and at the same time we continue to possess a sin nature and practice sin. This is based on four biblical truths:
We are all born sinners with a sin nature
Every person born into this world—with the exception of Jesus—is a sinner. We are sinners because Adam’s original sin is imputed to us (Ps. 51:5; Rom. 5:12, 19; 1 Cor. 15:21-22), we are born with a sinful nature which urges us to sin (Rom. 7:14-25; Gal. 5:17), and we choose to sin when we yield to temptation (Jas. 1:14-15). Sin is anything that is contrary to the holy character of God. Sin permeates every aspect of our being and renders us separated from God and helpless to save ourselves (Rom. 5:6-10; 6:23; Eph. 2:1-3).
God has provided for our salvation
The good news of the gospel is that Jesus took our sin upon Himself and bore the punishment that rightfully belongs to us (1 Cor. 1:18, 21; 15:3-4; Col. 2:13-14; 1 Pet. 2:24). This is substitutionary atonement, in which Jesus died in our place, “the just for the unjust, that He might bring us to God” (1 Pet. 3:18; cf. Rom. 5:6-10). Jesus paid the redemption price for our sins (Mark 10:45), and calls us into fellowship with Him (Acts 26:18; Col. 1:13-14). Salvation comes to us only as a free gift from God (Eph. 2:8-9; Tit. 3:5), “being justified as a gift by His grace through the redemption which is in Christ Jesus” (Rom 3:24). God is completely satisfied with the death of Christ, who “is the propitiation [ἱλασμός hilasmos – satisfaction] for our sins; and not for ours only, but also for those of the whole world” (1 John 2:2; cf. Rom. 3:25; 1 John 4:10). At the cross, God judged our sin as His righteousness requires and provides us salvation as His love desires.
We receive a new nature at the moment of salvation
At the moment we place our faith in Jesus Christ as our Savior we are born again (John 3:3; 1 Pet. 1:3, 23), and we acquire a new nature that desires to do God’s will (Rom. 7:21-23; 2 Cor. 5:17; Eph. 4:22; Col. 3:9-10; 1 John 2:29; 3:9). In addition, our identification with Adam is cancelled and we are immediately united with Christ (Rom. 5:14-18; 1 Cor. 15:22), we are indwelt with God the Holy Spirit (1 Cor. 6:19-20; Eph. 1:13-14), forgiven all our sins (Eph. 1:7; Col. 1:14), given eternal life (John 3:16; 10:27-28), bestowed with God’s own righteousness (Rom. 5:17; 2 Cor. 5:21; Phil. 3:9), and have the power to live righteously (Rom. 6:1-13; Tit. 2:11-14).
Christians continue to possess a sin nature after salvation
Though we have our new nature in Christ at the moment of salvation, we continue to possess our sinful nature, and this produces internal conflict throughout our Christian life (Rom. 6:6; 7:14-25; 13:14; Col. 3:9; Gal. 5:16-17). This reality explains why Paul tells the Christians at Rome to “put on the Lord Jesus Christ, and make no provision for the flesh in regard to its lusts” (Rom 13:14; cf. Rom. 6:6; Col. 3:9), and to the Christians at Galatia to “walk by the Spirit, and you will not carry out the desire of the flesh” (Gal. 5:16). Though we struggle with sin, we are assured that “there is no condemnation for those who are in Christ Jesus” (Rom. 8:1), for we are “the righteousness of God in Him” (2 Cor. 5:21; cf. Rom. 5:17; Phil. 3:9). Both are true. We are perfectly righteous in God’s sight because of the righteousness of Christ imputed to us, and we continue to possess a sin nature and commit sin.
The person who has thus received the gift of faith Luther described as “at once righteous and a sinner” (simul iustus et peccator). Formerly he had understood this term in the Augustinian sense of “partly” a sinner and “partly” righteous. …Now, however, while retaining the paradox of simultaneity, he sharpened each of the clashing concepts into a sovereign, total realm. Luther continued to use simul iustus et peccator after 1518-19, but he did so in the sense of semper (always) iustus et peccator. The believer is not only both righteous and sinful at the same time but is also always or completely both righteous and sinful at the same time [emphasis added]. What does this mean? With respect to our fallen human condition, we are, and always will be in this life, sinners. However for believers life in this world is no longer a period of doubtful candidacy for God’s acceptance. In a sense we have already been before God’s judgment seat and have been acquitted on account of Christ. Hence we are also always righteous.
So then, as Christians, we are simultaneously righteous and sinners. We are righteous in God’s eyes because of the righteousness of Christ that is imputed to us as a free gift (Rom. 5:17; 2 Cor. 5:21; Phil. 3:9). And, we continue to possess a sin nature that continually causes internal temptation and conflict (Rom. 6:6; 7:14-25; 13:14; Col. 3:9; Gal. 5:16-17, 19). Though the power of the sin nature is broken (Rom. 6:11-14), the presence of the sin nature is never removed from us until God takes us from this world and gives us a new body like the body of Jesus (Phil. 3:20-21).
Steven R. Cook, M. Div.
- The Sin Nature within the Christian
- I am a Saint
- The Gospel Message
- Soteriology – The Study of Salvation
- Believe in Jesus for Salvation
 Timothy George, Theology of the Reformers (Nashville, Tenn., Broadman and Holman publishers, 2013), 72.