And Jesus answered and said unto him, Blessed art thou, Simon Barjona: for flesh and blood hath not revealed it unto thee, but my Father which is in heaven.
And I say unto thee, That thou art Peter, and upon this rock I will build my church; and the gates of hell shall not prevail against it.
And I will give unto thee the keys of the kingdom of heaven:
and whatsoever thou shalt bind on earth shall be bound in heaven; and
whatsoever thou shalt loose on earth shall be loosed in heaven.
— Matt. 16:17-19
In order to understand exactly what Christ Jesus meant by giving Peter the keys to the kingdom of heaven, it is first necessary to gain a logical idea of the meaning of the term "kingdom of heaven." Instead of thinking of heaven as a place to which we will go for eternal rest after being loosed from "the mortal coil," let us follow the Scriptures and think of it as a state of consciousness. "The kingdom of heaven is within you," we are told, and we may take this literally and apply it scientifically in our daily lives to unfold the spiritual power within which enables us to contact and function on higher planes.
There are seven planes of being in our universe, and to enter and function consciously on these planes we must have the spiritual keys to them. It was to such keys that Christ Jesus referred, and Max Heindel tells us that actually these are "musical 'keys' or incantations such as are used in all occult orders and for all occult purposes. The modern Masons have something similar, for they furnish the lodge differently for each degree. They use different passwords and different grips, so that a Mason, though he may be initiated in some degrees, is as effectually barred from all others as a stranger, because he has not the 'keys' that unlock the doors. In occult orders like the Rosicrucians, the keynote of the incantation intoned at each degree is of a different vibratory measure from the keynote of all the other degrees, and one who has not the key and is unable to attune himself to it is halted as it were by an invisible wall of vibration which surrounds the Temple.
"There is a different vibration in the ether of the lower desire world, surrounding the earth, which constitutes hell, from that which prevails in the part of our atmosphere which constitutes the upper desire world and the region of Concrete Thought. This rate of vibration again differs from the pitch of the states of matter which are inside the earth, in each of the nine subterranean strata. Therefore, each of these divisions of the invisible world also requires a different keynote, which is gradually taught Initiates as they progress upward on the path toward Adeptship, and it was the 'keynote' to one or more of these various realms that was given to Peter and others by Christ, Who was the Initiator in their case.
"The same 'keys' are now given to His followers by His
successors who initiate worthy ones into the mysteries that they may serve
their fellow men better in a larger sphere of endeavor.Thus music has a
greater mission than simply to provide enjoyment for us; in fact, the harmony
of the spheres is the basis of all evolution. Without that, there could be no
progress, and when once our ears have become attuned to that, we have the
'key' to all advancement."
— Rays from the Rose Cross Magazine, November, 1975, page 505