Let's consider that last question from another perspective. Those who have done linguistic, mythological, and historical analysis of the Bible have noticed that the King James Bible has a lot erasers in it! The King James Bible almost seems like it was written to hide all kinds of linguistic, mythological, and historical errors(without finding them all). How did the writers of the King James bible know about all these errors and embarrasing sayings and so on? I attribute it to the pre-renaissance renaissance begun by the, Jewish, translations of Greek texts in Arab spain around 1000 A.D. There, Europe actually started the critical analyses of the Bible for hundreds of years before the 1600 conferences and writeup of the King James bible. If so, we could also have our answer on how an understanding of sungod worship could have been discovered by lowly Thomas Paine(I'm sure he just picked up on it from others he was in contact with).
Believe it or not, I'm not into the whole conspiracy stuff of the Illuminatti, and the Knights templar as shown by the "Da Vinci Code" writer. Although, I do consider christianity more or less a conspiracy(I don't think you can send a blood line from todays anybody christian rulers all the way down to Eusebius, Origen, Iraneus, Justin Martyr and so on; i'm sure there were times when people picked up on some manuscripts and filled in the blanks or assumed it was some ancient knowledge; in fact, recently, I've started to think just that happened after the Emperor Hadrian sacked Israel for the last time in 125 A.D. Then, people a generation later(15 to 20 year olds like Iraneus, Origin, Tertullian) would have picked up on various manuscripts laying around the Library of Alexandria and filled in the holes of what must have happened(as recently decoded by Robert Eisenman in his James Brother of Jesus; Jesus Christ is just a helllenistic sungod overwrite for James the Just).)
How indeed did Thomas Paine have such a clear idea of sungod origins of Christianity!?
"IT is always understood that Free-Masons have a secret which they carefully conceal; but from every thing that can be collected from their own accounts of Masonry, their real secret is no other than their origin, which but few of them understand; and those who do, envelope it in mystery.
A: East and West.
Q: Why so?
A: Because all churches and chapels are, or ought to be so.
A: In the East.
Q: Why so?
A: As the Sun rises in the East and opens the day, so the Master stands in the East, (with his right hand upon his left breast, being a sign, and the square about his neck,) to open the Lodge, and set his men at work.
A: In the West.
Q: What is their business?
A: As the Sun sets in the West to close the day, so the Wardens stand in the West, (with their right hands upon their left breasts, being a sign, and the level and plumb rule about their necks,) to close the Lodge, and dismiss the men from labor, paying them their wages.
A: East, West, and South.
Q: What are their uses?
A: To light the men to and from their work.
Q: Why are there no lights in the North?
A: Because the Sun darts no rays from thence.