What was the relationship between Radha and Krishna. What was so special about their relationship that even Krishna's wife did not get the same place as Radha?

Question - Gurudev, what was

the relationship between Radha and Krishna. What was so special about their relationship that even Krishna's wife did not get the same place as Radha? 

Gurudev Sri Sri - Though I have never read the Srimad Bhagavatam but I have heard that it is mentioned that Radha is not mentioned anywhere. The very meaning of the word 'Radha' means to return to your source. 'Dhara' means that which comes from the source, while 'Radha' means that which goes back to the source. So Radha is a Shakti (divine power). Until we go to the source we cannot experience Lord Krishna. Why is it so? It is because Lord Krishna is the source and Radha is the way or path to the source. So even if you are Rukmini or Satyabhama (the main wives of Lord Krishna), till you become Radha, till you return to the source, you cannot attain Lord Krishna. This is the hidden meaning behind this symbolism.