Universe's evolution is driven by a design pattern of an external observer driving the evolution, just by observation. We call this observer, the Atman and the evolution as Brahman. If we develop that detached observation capability in us, the ultimate isolation of mind (ekAnta), then we are in a state similar to that of Atman.
There are five phases in this process.
- The first phase is do our work with knowledge, but without desires. At the same time, remove all defects in our work to wash away sins.
- The second phase is to develop devotion to an external god so that we don't get attached to the results of our work. It is also the time we learn the vedic verses from other learned people.
- The third phase is to understand the vedic verses on our own, understanding other arguments and comparing it with vedic revelations. It is also the time to develop that 'Iam Brahman' attitude and abandon the 'I am body' attitude.
- The fourth phase is to eat food as medicine, be indifferent to desires or mercy of people and speak measuredly and never be cruel.
- The fifth phase is to develop ever happy isolated mind in equilibrium without ego or thoughts of future. One develops an 'observer' mentality. Then that supreme evolution driving observer of Universe is said to manifest in them.
For more details, refer here
sAdhana panchakam translation in tamil, essence in englsih, correlated with discourses from mahAperiyavA.