Bhagavan Sri Krishna, during the Dwapara Yuga - before the start of the Kurukshetra war, advised Warrior Arjuna on the ultimate truth of life, difference between Atma and Body and many other important aspects needed for this life and after that. This is called Srimad Bhagavad Gita! Though it was told to Arjuna, it is still applicable in today's world in many aspects of our life like: Management, Philosophy, Motivation, Health, Mind & Body, Life Coaching, etc.
So, let's keep Sri Krishna Paramatma's Bhagavad Gita close to our heart and try to incorporate Bhagavan's advice in our lives as much as possible!