This reflection on kamma, like the other four reflections, teaches heedfulness. But it also teaches confidence: That through the power of our actions, we can find a way out of the sufferings of repeated birth and death.

"This reflection on kamma, like the other four reflections, teaches heedfulness. But it also teaches confidence: That through the power of our actions, we can find a way out of the sufferings of repeated birth and death. We keep in mind the fact that our only true possessions — given that we are subject to aging, illness, death, and separation — are our actions and their results. Ajaan Suwat liked to comment that the Buddha often teaches that this thing is not-self, that thing is not-self, this thing is not mine, that thing is not mine, but then would have you say to yourself, “I am the owner of my actions.” In this case, the sense of “I” does not increase your clinging. It actually makes you more heedful of your only real treasures — your actions and their results — and confident that developing skillful actions will really make a difference. So the “I” here is a useful “I” to develop for the sake of following the path.

Now, if you look at your actions over the past week or so, what kind of treasures are they? Are they something that you want to put in a suitcase and carry with you on into the future? If they’re not, you know what to do this week. You have to act in ways that will create treasures that you would like to keep with you. You have to treat your actions as your most important possessions."

~ Thanissaro Bhikkhu "The Karma of Mindfulness: The Buddha's Teachings on Sati and Kamma"