When one lacks mindfulness, they can commit any kind of evil deed.
Right View (Sammā-diṭṭhi) is clear, correct, and truthful understanding. When the mind has Right View, it knows and understands what is evil and what is good, and it knows and understands the methods for abstaining from evil and the methods for doing good.
Mindfulness (Sati) is the awareness of being a human and how to conduct oneself properly in every moment so that one's life will progress, be peaceful, and be secure. When a person lacks mindfulness, they can commit all kinds of evil deeds, even killing other humans, which is no different from the cruelty of animals attacking and devouring other animals.
Mindfulness or Appamāda (non-negligence) is crucial every moment. Going to hell or the lower realms is because of the lack of mindfulness, not because of others' cursing or blaming. Going to heaven or attaining Nibbāna is because of mindfulness, not because of others' praise.
Others' wrongdoing serves as a lesson for us, while their good deeds can inspire and encourage us. But ultimately, merit and demerit are personal - no one else can create karma for us, only we can.
Developing mindfulness through meditation or mental cultivation is the way. We can train our minds to be mindful starting from today, and then we will no longer commit any evil or unskillful actions.
Some simple ways to train mindfulness:
Download and read the pdf file at
http://3pidok.com/files/download/satikantha.pdf
Download and listen to the audio files at
https://www.dropbox.com/sh/ojg05yzrl4yvg54/AAAH1p2JcsNo12Kqfr4mKbk2a
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