Very interesting. The teachings of the Buddha are very detailed and complex. I wonder if the followers of the Vedic system introduced the concept of a soul to present a easy to understand
theory of rebirth and continuation of life or if such a concept was already existing during the Buddha’s time.
It is interesting to note that the teaching of Adi Shankara explains liberation as merging into
brahman, after which one ceases to exist. He explains his concept of liberations as ‘Moksha’ where one experiences unlimited bliss and becomes one with Brahman and cease to exist. He teaches that the world is an illusion and there is no concept of eternal God.
Then Ramanuja after about 500 years later, introduced the concept of eternal existence and bliss in a spiritual world which is a lot more appealing to the common man. It is similar to Christianity where one eternally serve God.
I wonder if spiritual teaching were being modified and simplified to make it more appealing to attract more followers.
Also the teachers who certainly were great beings did what was essential for the good of humanity and their goal was to encourage people to live a moral life. Teachings were modified according to time and circumstances.
There is a theory that great teachers have come from immemorial in history to teach what was
relevant according to time and circumstances in different parts of the world.