I just googled where this came from and it involved a paragraph about Martin Luther King. I think you have to know a little about US history in this context. During Martin Luther King's time, he was all about being non violent. He asked that his people should not retaliate even if they are beaten. In that case, the beating means the suffering. If you can endure the suffering you can create change for a better society. A better society is the "redemption" in a sense.

Sometimes phrases have multiple meanings. It's hard to know the exact meaning this phrase stands for. However I can tell you unearned suffering is pain that is not deserved and that redemptive means to act to save someone from evil. I'm sorry if this doesn't fully answer your question.