Answer
In his first letter to the Thessalonians, Paul focuses on encouraging new Christians in the faith and inspiring them to pursue godly living. As he closes this personal, instructive, and uplifting letter, Paul offers hope-filled reassurance. Followers of Jesus Christ have the incredible opportunity to experience an extraordinary Christian life because God’s faithfulness underpins their faith: “Now may the God of peace himself sanctify you completely, and may your whole spirit and soul and body be kept blameless at the coming of our Lord Jesus Christ. He who calls you is faithful; he will surely do it” (1 Thessalonians 5:23–24, ESV).
The “he” who calls you is the “God of peace” (1 Thessalonians 5:23). What He will be “faithful” to do is “sanctify you completely.” His goal is that “your whole spirit and soul and body [may] be kept blameless at the coming of our Lord Jesus Christ” (verse 23, ESV). Paul’s assurance is based on God’s faithfulness. In the original Greek, the adjective for “faithful” means “reliable, trustworthy, permanent.” The term describes someone whose steadfast affection and allegiance can always be counted on. Paul wants new believers to know, “You are not alone!” The God who calls you to holy living (see 1 Thessalonians 4:7; Romans 12:1) has promised to give you the strength and grace to walk in holiness (see Romans 4:21). God has not left you on your own to figure it all out. He is always with you; He who has called you is faithful.
Yes, we have a responsibility to be spiritually alert (1 Thessalonians 5:6), “hold on to what is good,” and “reject every kind of evil” (1 Thessalonians 5:22). We are expected to pursue personal holiness through obedience to God. But believers can rest in the knowledge that the call of God is accompanied by His faithful empowering to see it through to the end (see 1 Corinthians 1:8–9). The writer of Hebrews confirms: “Let us hold unswervingly to the hope we profess, for he who promised is faithful” (Hebrews 10:23).
God has pledged to equip us to lead godly lives and transform us into the image of Christ (2 Corinthians 3:18; see also Colossians 3:10). He called us (1 Thessalonians 2:12) and chose us (1 Thessalonians 1:4) “to become like his Son” (Romans 8:29, NLT). God is faithful to finish what He started. He called us, and He will fulfill His plan for us. “And I am certain that God, who began the good work within you, will continue his work until it is finally finished on the day when Christ Jesus returns” (Philippians 1:6, NLT; cf. Psalm 138:8). He is the Potter, we are the clay, and He molds us into the people He wants us to be. His hands are sure, His intentions are wise, and His work is flawless.
Without God’s faithfulness, we are powerless to live the victorious Christian life. We cannot accomplish the work of sanctification on our own or make ourselves holy. Sanctification is the unique work of the Holy Spirit (Romans 15:16; 1 Corinthians 6:11; Galatians 5:5; 2 Thessalonians 2:13). King David experienced heartbreaking personal failures but learned to trust in God’s faithfulness and unfailing love. He wisely advised, “Give your burdens to the Lord, and he will take care of you. He will not permit the godly to slip and fall” (Psalm 55:22, NLT).
Every day, believers must cling to the Lord for help, for He is our source of sustaining power. Again, King David insisted, “Commit everything you do to the Lord. Trust him, and he will help you” (Psalm 37:5, NLT). When we are weak and discouraged, the Lord says, “Come to me, all you who are weary and burdened, and I will give you rest” (Matthew 11:28).
The God who called us is faithful to help us in times of temptation: “No temptation has overtaken you except what is common to mankind. And God is faithful; he will not let you be tempted beyond what you can bear. But when you are tempted, he will also provide a way out so that you can endure it” (1 Corinthians 10:13). Even if we do fall short and give in to the temptation to sin, God’s Word promises, “If we confess our sins to him, he is faithful and just to forgive us our sins and to cleanse us from all wickedness” (1 John 1:9, NLT).
The God who called us is faithful to strengthen and protect us from the evil one (2 Thessalonians 3:3). His trustworthy promises are our armor and protection (Psalm 91:4). Like Joshua, we can know deep in our hearts that every promise of the Lord our God will come true. “Not a single one has failed!” (Joshua 23:14, NLT). We can always count on the Lord and draw great hope from this truth: “Because of the Lord’s faithful love we do not perish, for His mercies never end. They are new every morning; great is Your faithfulness!” (Lamentations 3:22–23, HCSB).
