Locke, Jacob, and the smith

Recently, a friend mine and fellow lost lover, had a thought which, after much conversation, has grown into a theory we think could be the ultimate answer to our questions.

Since the beginning of the show, music has been an intergral part of lost. Songs featured and referenced in the show have shed light on many mysteries. Now I belive one song may hold the answer's to many of the most pressing mysteries.

John Jacob Jingleheimer Smith,
His name is my name too.
Whenever we go out
The people always shout,
"There goes John Jacob Jingleheimer Smith."
Da, da, da, da, da, da, da, da
John Jacob Jingleheimer Schmidt,
His name... [repeat]

Here we have conclusive proof that not only are Locke and Jacob the same person, but that they also manifest themselves in our beloved Smith, and, in this form, they will be the promised messiah of the island.
The song is sung from the perspective of Locke, as he describes his true purpose on thee island. "John Jacob Jingleheimer Smith, His name is my name too." The first line of the song show us that John and Jacob have the same name, and that John's true name is not Locke. As we continue we read the lines "Whenever we go out/ The people always shout, 'There goes John Jacob Jingleheimer Smith.' " These contain obvious messianic prophesies. The symbiont entity John/Jacob (Jocob, Jacohn, John Smith) is the savior of the island, and when they got out, the people will shout "There goes John Jacob Jingleheimer Smith."
Da, da, da, da, da, da, da, da. Notice also the eight da's, which hold obvious numerlogical meaning to lost.
Lastly the song repeats itself, with each successive verse becoming softer with a greater emphasis on the name of the messiah. This represents a time loop. All of the losites are in a time loop, as evidenvced by Desmond's visions/memories of previous journeys through the loop. Each time the loop repeats, there is more emphasis on the John/Jacob messiah, until the final verse, which is the loop of time that we are seeing in the show. In the final iteration of the events, John/Jacob is given the greatest emphasis in the song and he finally fulfills his duties as saviour of the islannd.
Still, why is Jacob invisible. This is because, though Locke and Jacob are the same, they are also twins (Jacob is the evil one). They were separated at birth when Jacob was sent to the island. Since his arrival on the island he has been studying to become what his name declares that he is, a Smith. As we learn from our most beloved Smith, the Poopsmith, Smith's are required to take a vow of silence. On the island this includes all communication through sound and sight. So Jacob has trained his sneak skill from his youth, so that he can move around the island unseen, and so keep his vow. This is why when Jacob breaks his vow by speaking to Locke, he becomes visible. (Also I will assume that what Ben mistook for Jacob speaking to him was actually his fillings picking up the television signals of reruns of Jackie Chan Adventures)