>>3653845Bad thoughts and attitudes arise due to incorrect views. The solution is not in practicing concentration in order to be able to better ignore these but to replace the incorrect views that generate them in the first place with Right Views that make your expectations match up to reality. Practicing jhana only represses those bad thoughts so they don't arise for a while. When holding incorrect views the mind is programmed to automatically create bad thoughts all the time, and you can only ignore them for a limited period of time no matter how high your concentration is. The actual way to achieve peace of mind is to stop generating these bad thoughts in the first place so you can get the most of Right Concentration instead of having to use up all your concentration to fight the swarm all the time.
By internalizing the Noble truths you cut the source of the problem since your expectations match up to reality and you realize the futility of getting angry, sad or greedy in the first place. Practicing jhana just to fend off bad thoughts (anger, sadness, greed, depression, etc) is just misguided effort, instead you should just realize how pointless it is to have these thoughts and you will no longer generate them, achieving way more easily the peace of mind you so desperately and unsuccessfully tried to achieve with self induced jhanic states.
In short, putting jhana (concentration) before nana (knowledge of nature) is like putting the cart before the ox. It's like practicing and getting really good at how to clean yourself while you're still up to your hips in the mud. First you have to cut the source of the problem, being stuck in the mud (aka wrong views).
I have taken this both from the study of discourses (suttas), by reading other people's experiences and by my very own personal experience. I hope it's helpful in some way..