For my part I believe in the forgiveness of sin and the redemption of ignorance.

The line contrasts two human failings—moral wrongdoing (“sin”) and lack of knowledge (“ignorance”)—and pairs each with a hopeful remedy: forgiveness for the former and “redemption” (education, enlightenment, correction) for the latter. Read this way, Stevenson is expressing a humane, liberal faith in improvement: people should not be permanently condemned either for ethical lapses or for being uninformed, because both can be addressed through mercy and learning. The phrasing also implies a civic ethic: public life should make room for repentance and rehabilitation, and it should treat ignorance not as a vice to punish but as a condition to remedy through better information and instruction.