James also wrote along this line: “Blessed is the man who endures temptation; for when he has been approved, he will receive the crown of life which the Lord has promised to those who love Him.” (Jas. 1:12). The message of this verse matches that of those noted above. James is writing to Christians, referring to them as “My brethren” (1:1; 2:1; 3:1). The “man who endures temptation” is a brother in Christ who faithfully endures, without succumbing to, whatever temptations the devil throws at him. At the end of his life of faithful endurance, “he will receive the crown of life.” The same basic thought is expressed in Jas. 1:25. The Christian who continues to live by the gospel of Christ, “and is not a forgetful hearer but a doer of the work, this one will be blessed…”
Peter’s second letter gives the same instruction. He’s writing to Christians, “those who have obtained like precious faith with us…” (2 Pet. 1:1). He instructs, “Therefore, brethren, be even more diligent to make your call and election (their eternal salvation) sure…” He goes on, “for so an entrance will be supplied to you abundantly into the everlasting kingdom of our Lord and Savior Jesus Christ.” (2 Pet. 1:10-11). The phrase “for so” carries the meaning “as a result of.” Their diligent faithfulness would result in their being given a home in Heaven.
What of John, writing about a brother in Christ committing a sin “leading to death” (1 Jn. 5:16)? Earlier John stated, “if we confess our sins, He is faithful and just to forgive us our sins and to cleanse us from all unrighteousness.” (1 Jn. 1:9). The word “if” is conditional. What if a Christian, having sinned, does not confess his sins? Paul declared, “For the wages of sin is death…” (Rom. 6:23).
Peter also warned to be sober and vigilant, “because your adversary the devil walks about like a roaring lion, seeking whom he may devour.” (1 Pet. 5:8). But how can the devil “devour” a saved Christian if that Christian cannot be lost once he is saved? Obviously, the warning is that a person can lose his/her salvation if they do not remain diligently faithful. That is why Jesus emphasized being “faithful unto death, and I will give you the crown of life.” (Rev. 2:10).