Christianity was introduced to Japan by St. Francis Xavier in 1549, inspiring many to become serious Catholic believers. As an international trading port developed by the Jesuits, Nagasaki played a central role for Christianity in Japan. However, fearing its growing influence, the Samurai shogunate implemented a strict ban on the faith. This dark age of severe persecution lasted for over 250 years, leading to the martyrdom of countless believers, particularly in Nagasaki. I will use materials and artwork from the Japan 26 Martyrs Museum to present the extraordinary endurance and unique aspects of the Christian faith as it was secretly preserved in Nagasaki by the “Hidden Christians.” Finally, I will discuss the profound and often overlooked connection between this long history of persecution and the devastating moment when the atomic bomb was dropped on Nagasaki many centuries later, explaining why this city became the focal point for both suffering and salvation.