Near the end of 1 Peter we read this: “I have written to you briefly, exhorting and testifying that this is the true grace of God. Stand firm in it!” (5:12).
Peter’s letter was a sustained exhortation for believers to see the difficulties of the Christian life—namely, persecution—as normal. The life they had been called to was not one of ease, comfort, or social acceptance. Instead, through “various kinds of trials,” their faith was being tested and proved genuine (1:6-7). It was a calling that would require perseverance. Peter assured them that their present experience was what they should expect as followers of Christ, and he urged them to stay the course: “Stand firm in it!”
Jesus was the first to teach about the necessity of perseverance when He said to His disciples, “You will be hated by all because of My name, but it is the one who has endured to the end who will be saved” (Matt. 10:22). This sobering reality and requirement was then conveyed to the readers of nearly every New Testament letter.
Now I make known to you, brethren, the gospel which I preached to you, which also you received, in which also you stand, by which also you are saved, if you hold fast the word which I preached to you, unless you believed in vain. (1 Cor. 15:1-2)
It was for freedom that Christ set us free; therefore keep standing firm and do not be subject again to a yoke of slavery. (Gal. 5:1)
Finally, be strong in the Lord and in the strength of His might. Put on the full armor of God, so that you will be able to stand firm against the schemes of the devil. . . . Take up the full armor of God, so that you will be able to resist in the evil day, and having done everything, to stand firm. Stand firm therefore . . . (Eph. 6:10-13)
Therefore, my beloved brethren whom I long to see, my joy and crown, in this way stand firm in the Lord, my beloved. (Phil. 4:1)
[Christ] has now reconciled you in His fleshly body through death, in order to present you before Him holy and blameless and beyond reproach—if indeed you continue in the faith firmly established and steadfast, and not moved away from the hope of the gospel . . . (Col. 1:22-23)
For this reason, when I could endure it no longer, I also sent to find out about your faith, for fear that the tempter might have tempted you, and our labor would be in vain. . . . for now we really live, if you stand firm in the Lord. (1 Thess. 3:4, 8)
So then, brethren, stand firm and hold to the traditions which you were taught, whether by word of mouth or by letter from us. (2 Thess. 2:15)
Take care, brethren, that there not be in any one of you an evil, unbelieving heart that falls away from the living God. But encourage one another day after day, as long as it is called “Today,” so that none of you will be hardened by the deceitfulness of sin. For we have become partakers of Christ, if we hold fast the beginning of our assurance firm until the end. (Heb. 3:14)
There is much more in the New Testament on the necessity of perseverance, but not enough space remaining in this article. Search for yourself to see how pervasive this theme is in Scripture. Also, don’t be disturbed by those who say that salvation by grace is incompatible with calls for diligent effort in enduring, persevering, keeping the faith. The same grace of God that saves sinners also produces the bravery and steadfast spirit that characterizes true believers.
Therefore, do not throw away your confidence, which has great reward. For you have need of endurance, so that when you have done the will of God, you may receive what was promised. For yet in a very little while, He who is coming will come, and will not delay. But My righteous one shall live by faith; and if he shrinks back, My soul has no pleasure in Him. But we are not of those who shrink back to destruction, but of those who have faith to the preserving of the soul. (Heb. 10:35-39)