The bible clearly teaches the reality of mortal sin and the possible loss of salvation . . .
The Bible describes sins that are mortal (or “unto death”) and those that are not mortal, which we commonly call venial (see 1 Jn 5:16-17).
Christians are capable of committing mortal sins, thereby rejecting the gift of eternal life, a gift that cannot be taken for granted. However, Christians who choose to persevere in faithfulness — and seek reconciliation through the sacrament of Confession should they sin — may be confident in God’s infinite mercy and his fidelity to his promises.
There are two closely related questions here. First, is it possible for a Christian to lose sanctifying grace (i.e., his salvation) by committing a serious sin? Second, if it’s possible for a Christian to commit such a sin, does this mean that our salvation is in jeopardy?
We must begin by realizing that at the heart of Jesus Christ’s mission was the proclamation of good news — God’s mercy to sinners. The angel announced to St. Joseph, “You shall call his name Jesus, for he will save his people from their sins” (Mt 1:21).
God’s mercy is greater than our sins. In the parables of the lost sheep, the lost coin, and the prodigal son, we discover the utter delight our Heavenly Father takes in showering his mercy on those who turn to him for forgiveness. Christians are called not only to experience reconciliation with God, but to be ambassadors of reconciliation to the world.
The fact that Christians may choose to sever their relationship with God through mortal sin demonstrates that in making us his sons and daughters through Jesus Christ, God leaves intact our free will and thus our ability to turn away from him. However, he is waiting to embrace each prodigal son and daughter who turn back to him. The possibility of mortal sin, then, should not be a cause for undue anxiety or worry.
The Bible makes a clear distinction between mortal and venial sin: “If anyone sees his brother sinning, if the sin is not deadly, he should pray to God and He will give him life. This is only for those whose sin is not deadly. There is such a thing as deadly sin, about which I do not say that you should pray. All wrongdoing is sin, but there is sin that is not deadly” (1 Jn 5:16-17).
Mortal sin is called “mortal” because it “kills” the life of grace in a Christian. Saint James speaks of saving a brother from mortal sin (Jas 5:19-20) and St. Paul notes that there are sins which, if unrepented, will prevent a person from inheriting the kingdom of God.
Some people teach the idea “once saved, always saved.” They claim that once a person has received Jesus, he can never lose his salvation. After all, since salvation can’t be earned (see Eph 2:8-9), how can it be lost? The Bible clearly teaches the reality of mortal sin and the need for repentance, endurance, and perseverance — remaining in God’s grace and not committing mortal sin — in the life of a Christian.
This column is reprinted with permission from “Faith Facts: Answers to Catholic Questions, Vol. 1,” by Leon J. Suprenant Jr. and Philip C.L. Gray (Emmaus Road Publishing, emmausroad.org, 1999).
Catechism 101
Sins are rightly evaluated according to their gravity. The distinction between mortal and venial sin, already evident in Scripture, became part of the tradition of the Church. It is corroborated by human experience.
Mortal sin, by attacking the vital principle within us — that is, charity — necessitates a new initiative of God’s mercy and a conversion of heart which is normally accomplished within the setting of the sacrament of Reconciliation.
Catechism of the Catholic Church, #1854, 1856