From what point of view is the story of The Chrysalids told; that is, who tells the story?

The chrysalids is told from David's Point of view, Him being the Protagonist - Even if the limelight is later stolen by his little sister Petra.
The significance in this story being told by him is that of HIM, as a child, understanding the biasness of the society. When the adults of the society are blinded by their beliefs that to begin with, were twisted.
As David once said "Ethnics was why you should, and shouldn't do things. Most of the Don't were the same as my father's but some of the reasons were different, so it was confusing. " It shows how the society and ethnics clash with each other and this confuses david to a large extent.
Using Sophie's Toe as an Example, To the society, having an extra toe meant that sophie was a blasphemy and she had to be removed as she was a threat to Waknuk. However, David wonders how one extra toe could cause any harm to anyone at all. Instead of viewing physical deformations as physical handicaps, the town views them as mutations and evil. The town views them as the source of evil instead of how it could be used to bring about productive , positive change.
Seeing things from David's Point of view is extremely advantageous to the reader as it shows the pure picture of the entire story. We can be sure of this as well, as David is the son of Waknuk's self-proclaimed Leader that constantly lectures and harps on purity of the race and how offences should be removed and purified as soon as possible, but David himself does not think like his father. Does not Conform to the society's standards and rules. However much is drilled into David, he still stays unbias-ed. It helps bring out the essence of the whole story, how the residents of Waknuk have been reading excerpts out of the repentences and claiming them to be god's words (repentences =/= bible), how they do not think for themselves. In the sense that they want to build society to how the old people had it, but do not think that because of the way that the Old People had built society, it brought tribulation down on them. It shows how progressive stances are brought to a halt. (Angus morton's Great Horses)
If anyone else in the book told the story, important key points might be left out.
Such as the messages hanging on David's House walls, showing the extremity of Waknuk. And also How making friends with sophie shows deviants are not born evil, they are forced to become cunning and of such because society forces them to be.