If an activity, book, etc. repays your effort, time, attention, etc., it is worth the effort or time, etc. that you spend on it.

You should read this article - it would repay your time. 你应该看看这篇文章，非常值得一读。

If you think of these children growing into adults who enjoy and appreciate classical music, then that repays our effort. 如果你认为这些孩子长大成人后会欣赏和鉴赏古典音乐，那我们的努力就没有白费。