In Advaita Vedanta, Brahman and Atman are literally the same ultimately. If you follow a dualistic religion, then they are not the same. Krishna can tell us to keep thinking about God - but that's not what he means. Buddha being convinced inevitably lead to minus being convinced to. So understanding requires conviction, clarity, and minus means thoughts.
Swami Sarvapriyananda teaches Chapter 8 (Verses 23-28) of the Bhagavad Gita. In this series of talks, Swami Sarvapriyananda unfolds the highest truths of Vedanta through the study of the Bhagavad Gita (The Song of God).