Bhagavan Sri Krishna said: Hear, O son of Pritha, how without doubt thou shalt know Me fully, practising yoga with thy mind fixed in Me and taking refuge in Me. (Bhagavad Gita Chapter VII, Verse I)
This is a great and wonderful promise that Bhagavan Sri Krishna makes to Arjuna. ‘Hear, how you shall know Me fully.’ Doubt not; believe My word. I am going to tell you all about Myself, that knowing Me, you may truly love Me and become entirely devoted to me. But you must practise yoga. That is, you must make your mind strong and steady and then fixing your mind on Me, you must take refuge in Me. Those who want material prosperity may follow the rules laid down in the shastras for that purpose, rules regarding austerities, sacrifices, vows and so on. But those who want to know Me in My infinite greatness and power and grace, must come to Me. They must abide with Me, then gradually all their doubts will vanish as they come to know Me fully.
It is a common experience of the devotee that one moment he is filled with faith, hope and security; he seems to understand and he is satisfied, but again he forgets. The mind becomes confused, early experiences are forgotten or they are doubted as to their value and nature. The mind wavers and loses faith.
Therefore we must practise love, devotion and intense attachment for Bhagavan. This is called yoga. This will make our faith strong and enduring.
Depending on Bhagavan, recognizing Him as our refuge, as our saviour, as the end and aim of our hopes and aspirations, we must try to feel the presence of God at all times, even during our various activities. That is practicing yoga. It is our first duty as declared in the opening verse of this chapter. Then, God’s promise will be fulfilled in us; we will know God. We will realize the Truth.
Sri Ramakrishna met God face to face. He knew his Divine Mother more intimately than we know our dearest friends. And the Vedas declare that we shall know God in just as real a sense as we know a fruit we hold in our hands. This then must be what Sri Krishna means when He promises to reveal Himself fully, that He will give to His devotee the realization of His Being. Sri Krishna promises to declare to Arjuna knowledge and realization. And mark how He speaks in praise of that knowledge.
Source - Prabuddha Bharata Magazine June 2003 edition page number 33.