All of the current Gatekeepers (original name of the series, now called Power of Five) had a past life where they had a different name. Eventually, probably because of their powers and the whole battle to save the world, they were viewed as gods of whatever cultural background they have. Their names are different in this lifetime because, as the past Matt said, you don't choose your own name.
Pedro was the son of the Sun God(?) and called Manco Capac. For some reason, (and I realized this when I reread Evil Star) Horowitz calls him Inti in Nightrise. Perhaps this is because the Incans have a day called Inti Raymi that has to do with the sun and is related to Manco.
In Nightrise, it is revealed that Jamie and Scott are the Native American gods, Sapling and Flint respectively. According to myth (not in the book), they created all the creatures and such but Flint, the evil twin, killed Sapling. It is different in Nightrise, but hey, it's not going to be exactly the same.
Scarlett is the Chinese water goddess Lin Mo, who sounds like she could probably also control the weather (Scarlett's power). In the past she is called Scar. Her name is probably similar to her past name because her father worked for Nightrise, and they probably knew who she was.
It is yet to be revealed what Matt's past name is. In Nightrise he told Jamie he prefers his future name. I speculate this is because he was a powerful god whose name shouldn't be known or, like his present self, didn't even want to have any part in this and doesn't like the attention his true name would bring him. At first I thought it might be God or Jesus, since Britain is Christian. That would be mind-blowing! But then I remembered that Britain used to be inhabited by the Celts, so Matt was probably a Gaelic god. The past Matt probably knows his future self's name because he gets visions of the future. That would explain how he seems to know so much. I like that theory better than the idea of him reading his future self's story in the library on the dream island.
Someone mentioned that Matt is the Buddhist Messiah. I don't remember Necropolis that much, but it's a possibility since I think Lohan said the Buddhist Messiah created the sword ladder? After all the past Matt and Inti created the 2nd gate at the Nazca lines and the meeting of the Five made the 1st, Raven's Gate. But then how was the internet of churches already in place so the past selves could meet? (Although in the past it wasn't churches. The churches were built there because someone recognized there was something important there.) Also, Buddhism, at least true buddhism, doesn't believe in dieties, only the Buddha as a teacher (still human) so could there really be such a thing as a Buddhist Messiah?
Note: The past selves were alive 1,000 years ago, not 10,000 years ago like it said in the forum.
Look at "What is the past name of Matt Freeman from the Gatekeepers series"? for the more detailed answer. To add to that: Matthew means "God's gift"
The fourth book of the Gatekeeper series is called "Necropolis" by Anthony Horowitz. It continues the story of the battle between good and evil as the Gatekeepers work to prevent the Old Ones from returning to Earth.
we are not sure but maybe as the pentagram series has 5 parts so will the gatekeepers but there are doubts that the name of the book has been come out. a guess made by some people is that the name of the book is 'the horror within'. but we can never be sure so look out for the name. As of September 2010 the name is still unreleased. Few have thought that the name was "the power of five", but that is just what the series is called in countries other than the US.
Gordon Freeman
the name of the gatekeeper is Zuul
Hal Freeman's birth name is Harold Freeman.
Jensen Freeman's birth name is Jonathan Freeman.
McKinley Freeman's birth name is David Freeman.
Freeman Michaels's birth name is Michael Freeman.
The name Freeman is used in the game Half-Life, in which Gordon Freeman is the character.
Freeman Dyson's birth name is Freeman John Dyson.
Alvin Freeman's birth name is Alvin Ray Freeman.