Henry's quote about a person's conviction in The Night Thoreau Spent in Jail can relate to modern times.
Thoreau is talking to Bailey, his cellmate, about why it is essential for individuals to act in accordance to their beliefs. When Thoreau speaks of "fire inside," he is talking about the convictions that people hold. He is trying to convince Bailey that the ideals in which people believe can be extremely powerful. They can inspire people more than a "flame or bullet or a rock." Thoreau suggests that ideas last longer than these objects. Fires can be extinguished while bullets die out, and rocks fall back to earth. Yet, ideas never die. They represent something "uncommon." While Bailey does not fully understand what Henry is saying, he knows that Henry is inspired and passionate about his beliefs.
Thoreau's feelings about the power of ideas can relate to current times. Protests are one such example where "the fire inside" is powerfully compelling. For example, this "fire" can be seen in the Black Lives Matter movement. The insistence on equality in American society represents the power of "the fire inside." Around the world, when the Arab Spring took place, the power of liberal, democratic change was a "fire" that was not only potent, but contagious when so many people in different nations insisted upon change. When teachers in Detroit, Michigan, refused to go to work in protest of deplorable conditions in schools, it shows the "fire" of beliefs. These situations help to relate Thoreau's ideas about people's beliefs being "uncommon" and they show "the fire inside" in current times.