From Yogananda's handwritten letter about being loyal to SRF and Kriya Yoga practice.
“I am sending to you immediately the wonderful things that came to me about Kriya Yoga and Pranayama.
Please strictly refrain from describing the technique of Kriya Yoga, which I indelible a part of our work for disciples only ………Kriya yoga indeed has a very popular appeal…..Everybody is anxious to receive it after reading the book Autobiography of a Yogi, and I am giving it to them only after they have received their foundation in the Preacepta lessons……..The science of Kriya Yoga is mentioned in the book but the road to Kriya yoga will be learned from SRF/YSS Headquarters.”
“ This is not the end of your relationship with SRF or Kriya Yoga – but the beginning. Keep contact with headquarters and you will be linked with the masters, by which salvation is reached quickly…….