"过去最伟大的真正改革者，如果今天回到这个世界，都会不寒而栗，担心他们的劳动是否已经无法挽回地陷入混乱。"

Simplified Meaning:

Imagine people who worked very hard in the past to make the world a better place. They fought for important changes and improvements, like fighting for freedom, rights, and justice. If these people could come back and see the world today, they might worry that their efforts led to some problems instead of solving them. Think about a famous leader like Martin Luther King Jr., who fought for racial equality. If he saw today's issues like ongoing racism or new challenges, he might feel concerned that not everything turned out as he hoped. The main idea here is that even the best efforts to create positive change can sometimes lead to unexpected or unintended consequences. When trying to apply this in our own lives, it's good to remember that while we try to make things better, we should stay vigilant and humble, recognizing that our actions might not always lead to perfect outcomes. This helps us constantly reassess and improve our efforts for a better future.