Answer
That is simply Mayavada philosophy.
Someone may even be an exclusive worshipper of Krishna and still speak exactly like this. However, their ultimate conclusion is different. They say that once they attain realization, they themselves become Krishna. They claim that self-realization and God-realization culminate in merging, where distinctions such as guru and disciple, God and devotee, all disappear.
According to them, as long as duality remains, one has not reached the highest truth. They consider all distinctions to be part of illusion, and they say that only non-dual reality is ultimately true.
They also speak about Saguna Brahman and Nirguna Brahman. They may say that worship of Krishna is acceptable as worship of Saguna Brahman, but ultimately one must transcend this and merge into Nirguna Brahman. Some even conclude that they themselves will eventually become Krishna.
This removes the eternal individuality of the living entity.
As I mentioned earlier, statements such as "I am not this body" can certainly be used properly because they are Vedic truths. Even Shankaracharya used such teachings. However, the Vedanta-sutra and the entire Vedic literature were compiled by Vyasadeva, who also wrote Srimad-Bhagavatam, the natural commentary on Vedanta-sutra and the essence of all Vedic knowledge.
That is why Sri Chaitanya Mahaprabhu warned that hearing Mayavada philosophy is spiritually dangerous. One may perform severe austerities, live a disciplined Vedic lifestyle, faithfully follow scriptural regulations, and even realize that one is not the body.
But realizing that one is not the body alone is not sufficient.
A Mayavadi may realize, "I am not this body," yet still reject Krishna as the Supreme Personality of Godhead. Instead, he concludes, "I am God," and uses his realization to place himself in God's position.
Ordinary materialists identify with the body for the sake of sense gratification.
A Mayavadi may go beyond bodily identification, but if he rejects Krishna's supremacy, he develops another form of false ego, believing that everything and everyone is ultimately under his own control. This mentality is exemplified by powerful atheistic personalities such as King Vena.
That is why Sri Chaitanya Mahaprabhu instructed us not to hear Mayavada explanations of scripture. Instead, we should hear philosophy from Vaishnavas.
When you study these topics through the explanations of the Vaishnava acharyas, you understand Sankaracharya's philosophy in its proper context, its intended purpose, and its historical role, without becoming influenced by its impersonal conclusions.
