For example, just because those who don't know mathematics decide to solve math problems from today doesn't mean that they can. Just because farmers who don't know farming very well decide to start farming well from this year doesn't mean they can. If you want to do something, you have to be someone who can do it.
Evil comes from ignorance. People don't know that if they do bad things, they end up with bad results. They want to do good things, but they don't know what is good and how to do it. To do right things, they must learn ways to do them and practice them with will and effort.