The English term apostasy comes from the Latin apostata and means ‘to move away from,’ while the Arabic term riddah means ‘turning back.’ Apostasy is therefore to renounce one’s religion and adopt another or no religion. Buddhism does not have a legalistic approach to belief and thus never developed a concept of apostasy, nor did any Buddhist cultures have such a concept. In Buddhism, the individual is free to believe or not according to his or her own inclinations and understanding. The Buddha’s attitude to apostasy is epitomised by his encounter with a man named Sunakkhatta. He was a disciple of the Buddha, but after a while became dissatisfied with the Dhamma and decided to renounce the Teacher and the teaching. Sunakkhatta came to the Buddha and said; ‘Lord, I am leaving you, I am no longer living by your teachings.’ The Buddha responded to this declaration by asking Sunakkhatta some questions. ‘Did I ever say to you; come, live by my teachings’. ‘No Lord’. ‘Then did you ever say to me that you wished to live by my teachings’. ‘No Lord’. ‘That being the case, who are you and what are you giving up, you foolish man?’ (Digha Nikaya 3. 2-3). Neither in this case nor others did the Buddha suggest that apostates be punished; nor did he say that apostates would go to hell simply because of their apostasy.
Buddhism A to Z. Ven. Dhammika, 2007.