Grace through works or grace through faith apart from works? Despite the many similarities, one conforms to God’s Word; the other does not. The Catholic doctrine of mortal sin brings this monumental difference to the surface
What Is Mortal Sin and Is it Biblical?
The doctrine of mortal sin is the Roman Catholic teaching that some types of sin cause a person to fall out of God’s saving grace (Catechism 1855-1856). Catholics apply this doctrine to themselves, because they believe nonbelievers were never granted salvation in the first place. Catholics consider a sin to be mortal if it is:
- severe in nature;
- committed in the full knowledge of the person
- committed in willful defiance of the Lord.
A person in this position will go to hell if they do not absolve the sin through the appropriate means of grace (Catechism 1446 & 1472). In this circumstance, Catholics believe God will forgive sin and restore their salvation if they earnestly repent and partake in the Sacrament of Penance, which involves confessing the sin to a priest who acts as a sin-forgiving mediator on the sinner’s behalf (Catechism 1495-1496).
What’s the Difference between Mortal Sin and Venial Sin?
In Catholicism, all sin falls into two categories: mortal sins and venial sins. As mentioned, mortal sins are severe transgressions that cause Catholics to fall outside God’s saving grace. Venial sins do not cause Catholics to lose their salvation, but they make Catholics spiritually unclean and need resolution. In Catholicism, purgatory revolves around the belief that Catholics who die in their unresolved venial sins must go through purgatory for cleansing before they can enter heaven.
What Does the Bible Say About Salvation?
The Catholic doctrine of mortal sin is not biblical. To get to the root of the issue, we must understand the nature of our salvation in Jesus Christ as revealed in God’s Word. Scripture teaches us God has removed all human effort from His work of salvation. Paul tells us we are justified by faith separate from works (Romans 3:28). If there is any doubt of Paul’s exclusion of all human effort for salvation, we should investigate Romans chapter 4. Here Paul cites Abraham as an example, saying he was deemed righteous when he believed God before his circumcision. In other words, before Abraham did any works of righteousness, God responded to his faith and secured his salvation. Abraham’s circumcision was merely a sign (Romans 4: 1-12). Catholicism teaches that God justifies us by faith through works (Catechism 1692).
Any time someone changes or adds to the conditions of salvation as revealed in Scripture, they change the gospel of Jesus Christ. That is why Paul issued a harsh rebuke to false teachers who do this, saying they are to be accursed (Galatians 1:8). Jesus’ work on the cross is perfect, finished, and sufficient. To say anything else is necessary for our salvation is to insult His perfect, loving sacrifice for our sin.
What Bible Passages Are Used to Support Mortal Sin?
This article cannot address all the passages of Scripture or teachings used to support belief in mortal sins, but it will focus on a few key points.
Interpretive errors can happen when we ascribe a fixed meaning to a word or phrase. Forgiveness, for example, can pertain to God releasing us from either the eternal or temporary consequences of sin. Even though believers cannot lose their salvation (Ephesians 1:13-14), they can still provoke God to anger with their sin, bringing judgment in this life.
Some of the ways God disciplines His children for their sin include sickness (James 5:14-16), hardships (Amos 4:6-11), and even physical death (1 Corinthians 11:30).
The Catholic notion that a priest has the authority to absolve a mortal sin’s eternal consequences comes from an incorrect understanding of certain passages about forgiveness. There is only one Mediator and one Priest capable of interceding on our behalf to save us from the eternal consequence of our sin—Jesus Christ (1 Timothy 2:5-6). There is no human agency through which God expenses His eternal grace.
How Do We Interpret 1 John 5:16?
Problems also come when we do not take the time to understand the context of a verse or passage. The Catholic teaching on 1 John 5:16 is a good example. This verse reads, “If anyone sees his brother committing a sin not leading to death, he shall ask and God will for him give life to those who commit sin not leading to death. There is a sin leading to death; I do not say that he should make a request for this.”
Catholics use this key passage to support their belief in mortal sins. First, we should acknowledge this is a challenging passage to understand. Whenever we encounter a difficult passage in Scripture, it’s wise to consult other clear passages to determine what a text cannot be teaching. God is the author of all Scripture (2 Timothy 3:16), and He cannot lie (Hebrews 6:18), which means His Word will never contradict itself. God is clear. Christ’s work of salvation cannot be undone. Believers can never lose their salvation (Romans 8:28-39), so this passage cannot mean that genuine believers lose salvation through certain sinful acts. Christian scholars have come up with several possibilities, and this article will present the three interpretations this author finds most feasible. The reader needs to do their own research to determine if the conclusions are faithful to Scripture.
- John reassures us all sin committed by a brother (true Christian) does not lead to condemnation. John’s mention of “a sin not leading to death” references a sin type or category not resulting in eternal condemnation. This kind of sin could only apply to true believers in Christ since faith in Jesus alone forgives our sins’ eternal consequence. In that case, the “sin leading to death” is John’s description of all sin committed by unsaved sinners, since they will be condemned for their sin. The immediate context provides strong support for this interpretation. John has just assured his readers they have eternal life in Jesus Christ (1 John 5:10-13). He does not want readers to question the security of their salvation. If we’ve been given eternal life in Jesus, how can our sin lead to death? It makes no sense for John to assure his readers of their salvation in Christ and immediately undermine what he is trying to accomplish by telling them they can lose their eternal life. Furthermore, this interpretation explains why John would tell his readers not to pray for sin leading to death. God will not grant life to those who reject the gospel (1 John 1:10-12).
- John refers to sins that cause a believer in this life to fall out of fellowship with the Lord. Fellowship is a recurring theme in John’s letter. He starts the letter by associating life in Christ with fellowship (1 John 1:1-3). It is not unreasonable to think sin leading to death refers to broken fellowship with Christ in this context. The passage says that God will give life to the brother (Christian) who sinned on behalf of another believer’s petition. First, God only grants eternal life in response to an individual’s faith, not on behalf of other Christians’ prayers. This makes it hard to believe John refers to eternal life in this verse. Since true Christians cannot lose their salvation, they can only experience death if they break fellowship with God through their sin. If this interpretation is accurate, John may instruct his readers not to pray in this manner for those who commit sin leading to death because God will only restore fellowship with the rebellious believer if they repent and return to Him.
- John refers to believers committing sin that God punishes with physical death. As mentioned already, sometimes God will take a believer’s physical life to protect the integrity of the church body and preserve the testimony of Jesus Christ. The Bible demonstrates this in the account of Ananias and Sapphira, recorded in Acts 5:1-10.
How Should Christians View Sin and Different Types of Sin?
Christians must take all sin seriously, but there are numerous examples where God does distinguish between types (or degrees) of sin (Numbers 15:22-31; Mark 12:38-40). The question is, how does God deal with it? There is a major difference between the way sin affects a believer’s life and a nonbeliever’s life. 1 John helps us understand the role sin has in the life of a believer. Sin will always be present in a believer’s life (1 John 1:7-10), but true believers do not tolerate it, nor do they live in it (1 John 3:9). Christians may undergo seasons of habitual sin, but they will repent and walk in faithful obedience if they truly belong to Christ. Genuine faith in Christ does produce works, but those works are the evidence of our salvation, not the means by which we are saved (1 John 2:3).
God could not be clearer about His exclusion of human works from His gift of salvation. The gospel teaches us we can rest from vain efforts to save ourselves and depend entirely on Christ’s completed work, which saves us from our sin. Obeying God is the inevitable disposition of all true believers, but not the condition of their salvation. It is the demonstration of the power of Christ working in their life. Our faith does not stand on shaky ground where we must always wonder if we took all the proper steps to make it to heaven. Our faith rests on the Solid Rock, Jesus Christ, who promised to give eternal life to all who trust in Him and His perfect work of salvation. To Him be the honor and glory forever and ever. Amen.
Stephen Baker serves as the Associate Pastor at Faith Fellowship Church in Minerva, OH where he is discipled by pastor Chet Howes. He is currently a student at Southern Baptist Theological Seminary. He is also the writer of a special Scripture study/reflection addendum to Someplace to Be Somebody, authored by his wife, Lisa Loraine Baker (End Game Press Spring 2022).