To be accurate, the BIONICLE story doesn’t really have any Christian influence. The earliest lore is an adaptation of the Maori creation myth, which is particularly obvious in MNOG, which was conceived early in the story’s development.
The Makuta is based on Te Kore (The Nothing; Void), the original darkness / destruction from which the world emerged.
“You cannot destroy me. No more than you can destroy the sea, or the wind… Or the void.”
"I bore you, for I am Nothing. And out of Nothing you came.
–Makuta, MNOG
Mata Nui is based on Te Ao (the Light) which originally emerged from the darkness.
“I stand with Mata Nui side by side. I am his brother.”
–Makuta, MNOG
(Note that Makuta mentions the sea and wind, which are the two primary aspects in Maori mythology to emerge from the light.)
The last bit of strong evidence is the reference to Papu and Rangi as creators of some sort, who clearly reference the mythological Papa and Rangi, the parents of various lesser deities in Maori mythology. (Although it seems references to the two were only left in MNOG accidentally.) It’s possible they were reworked into Artakha and Karzahni as the story developed.