"When i do good, i feel good.
When i do bad, i feel bad."
- Abraham Lincoln

The message in this quote is saying that we all do feel really good when we do the right things, doing the right things makes you fell like a very good person but when it comes to bad things of doing you feel bad, awful, failure. it makes you feel like full of regrets, i have done good and bad and it's true when you do good you feel good and when you do bad you feel bad. i think it tests your feeling like "oh let's see what doing good or  doing bad makes you feel."