Extracts from https://hackspirit.com/4-stages-enlightenment-according-buddhist-scripture-can-achieve/
The Buddha recognized four distinct levels of realization, each one characterized by a deep experience of selflessness, followed by certain changes in outlook.
The experience usually involved intensive meditation and follows study of the four basic truths of Buddhism.
If you’re regularly meditating and practising mindfulness, you’re probably already undertaking many of the practices that is advocated by Buddhism.
Here are the four stages of enlightenment.