Regarding your question about the term "unmanifest" in the Bhagavad-gita 8/21, there are two words in Sanskrit—aprakata which means "unmanifest" or "nonmanifest" and prakata which means "manifest". Krsna's Lila in Vrndavana is prakata or manifest Lila, and the same is going on eternally in the spiritual realm which is known as aprakata or nonmanifest. Actually Krsna's planet and Krsna's pastimes are going on eternally, and the same is manifested before the conditioned souls at certain intervals, that is to say once in one day of Brahma, exactly as the sun is visible for 12 hours once in a 24 hour cycle of day and night. When the sun is visible it is called prakata, and when the sun is not visible that is called aprakata or unmanifested. Nonmanifested therefore does not mean there is no existence, but the terms are used in relation to the visibility or nonvisibility to the limited conditioned souls.
Krsna by His causeless mercy manifests Himself along with His form, name, qualities, entourage, and pastimes in order to attract the conditioned souls to the eternal blissful life of knowledge. Thus by understanding Krsna in His manifest Lila one is attracted to His eternal Lila, and that is the highest success of life which is explained in the latter part of the verse
- yam prapya na nivartante
- tat dhama paramam mama
"Going, no one ever returns from that, My Supreme Abode."
Please offer my blessings to Sriman George and all the other Prabhus there. I am marking that George has the serving spirit, and that is making him advance gradually.