Verbum Domini Manet in Aeternum (The Word of the Lord Endures Forever) is the motto of the Lutheran Reformation, a confident expression of the enduring power and authority of God’s Word. The motto is based on 1 Peter 1:24–25. It first appeared in the court of Frederick the Wise in 1522. He had it sewn onto the right sleeve of the court’s official clothing, which was worn by prince and servant alike. It was used by Frederick’s successors, his brother John the Steadfast, and his nephew John Frederick the Magnanimous. It became the official motto of the Smalcaldic League and was used on flags, banners, swords, and uniforms as a symbol of the unity of the Lutheran laity who struggled to defend their beliefs, communities, families, and lives against those who were intent on destroying them. It was found inscribed inside churches, over doorways, on foundation stones, even on horse’s helmets! The VDMA logo and statement has appeared throughout Lutheran churches worldwide and remains an enduring motto of the Reformation to this day.

https://lutheranreformation.org/history/the-motto-of-the-reformation/