Martin Luther is famous for the Latin phrase simul justus et peccator, which means “simultaneously just (or righteous) and sinner.” In this phrase, he was communicating the theological understanding that the Christian is both justified/righteous and at the same time a sinner.
By faith, Christians are justified before God as their sins are pardoned and the righteousness of Christ is imputed to them. Yet, in the ongoing pilgrim life of the Christian, there is still a struggle with sin that is discouraging and that, sadly, may lead to devastating consequences. So, how does the Christian, who is justified in Christ, deal with the continuing presence of sin?
Remember Who You Are
First, we must remember who we are as those united to Christ by faith. The Apostle Paul writes in Ephesians 1 that we have been redeemed, adopted, forgiven, and given spiritual blessings, have obtained an inheritance, and more. These are tremendous descriptions of what we have in Christ by the grace of God. Therefore, our relationship to sin has been utterly changed, and how we respond to sin comes from our understanding of who we are in Christ. We must constantly remind ourselves of who we are in Christ and what Christ has done for us.
The Means of Grace
Let me offer a few practical ways to do this. Make sure that you are a part of a church with a minister who preaches the gospel every week. The gospel reminds us of who we are in Christ and what Christ has done for us.
Also, in your church, take seriously the sacrament of holy communion. In the Lord’s Supper, we have a physical sign and seal of what Christ has done for us. The preaching of the Word and the administration of the Lord’s Supper are means of grace that encourage us in our lives and again remind us of who we are and what we have received in Christ.
The Armor of God
Of course, even with our understanding of who we are in Christ, we still face regular temptations. Each Christian’s temptations are not the same, but we all struggle with sin as we seek to pursue the holiness that God desires.
The Apostle Paul again calls us to stand firm by putting on the “whole armor of God” (Eph. 6:10–20). We need the belt of truth, the breastplate of righteousness, the shield of faith, the helmet of salvation, and the sword of the Spirit.
The battle imagery is absolutely appropriate. We must do battle with things that would cause us to fall away from God. This is a constant fight that will not end until we reach heaven. Thankfully, the Holy Spirit is at work in us and will help us in our struggle until that day when we will be glorified and our struggle with sin ultimately will end.