In 5:20 James also says that the one who turns such a sinner, such a backslidden brother, will save his soul from death. We need to pay attention to the fact that James does not say “save him,” but says, “save his soul.” We need to differentiate “saving him” from “saving his soul.” What we have in verse 20 is a matter of the salvation of the soul.
In this Epistle James has already spoken concerning the salvation of the soul. In 1:21 James says, “Wherefore, putting away all filthiness and abundance of malice, receive in meekness the implanted word, which is able to save your souls.” Saving the soul is not a matter of initial salvation; it is a matter of the progressing stage of salvation, the stage of transformation (see note 55 in 1 Peter 1). Those who have been saved initially need to receive more of the word that can save their souls. Hence, according to 1:21, after our initial salvation we still need a further salvation, the salvation of our soul.
The saving of the soul in 5:20 is not related to saving the person from eternal perdition; it is to save his soul from a certain kind of suffering. According to 1 John 5, sin may cause one’s physical death because of God’s discipline. A believer may sin and then be warned by God. If he ignores this warning and continues in sin. God may discipline him and allow him to become sick. This sickness is a discipline and also a warning to repent, forsake that sin, and give up a life of sinning. If this believer does not repent, God may discipline him further to the extent that He cuts short his physical life. As a result, this believer dies.
The fact that a believer may die as the result of sin does not mean that he will perish eternally. Once we have been saved, we are saved eternally. On the day we believed in the Lord Jesus we were saved once for all, and we shall never be lost. However, if a believer remains in a life of sin, he may be warned and disciplined by God through sickness. First, God may discipline him with sickness as a warning to come back to the truth. Then the church may have someone try to bring this person back. But if this one remains in sin, this may force God to exercise further discipline and allow him to die.
Suppose you are burdened to turn a misled believer back to the truth. To turn him back is to save his soul from physical death. This is the proper interpretation of 5:19-20.
What James says in these verses has nothing to do with eternal perdition or eternal salvation. The question of eternal salvation was fully resolved at the time we believed and were saved. Nevertheless, if we are led astray and go back to sin, we may suffer sickness as God’s discipline. If we do not repent, we may suffer an early death.
When someone dies, it is the soul, and not the body, that especially suffers. Physical death is a very real suffering to the soul. To be saved in our soul from such suffering is to be brought back to the truth. This is what it means to bring back a backsliding believer and thereby save his soul from physical death.
What James describes in these verses is part of the church life. However, it is a negative aspect of the church life. In this Epistle we cannot find positive things covered by James with respect to the church life. Although what James says concerning the church life is on the negative side, we can still receive much positive help from what he has written in this book. In particular, we can receive help concerning practical Christian perfection.