Was the The Original Father Christmas was Christian?

Yes. The story of Santa Claus is believed to have originated from the real St Nicholas, who was born in Lycia, Greece (now part of southern Turkey) during the third century.

St Nicholas/Nicolas was brought up in a devout Christian family. His parents taught him to be generous and to serve others. He had a reputation for secretly giving to the poor, and he was also known for his love for children, and his concern for sailors who often worked under some difficult conditions.

Nicholas was persecuted for his faith under the Roman Emperor Diocletian, and died on 6 December 343.

Answer:

Like the superpositioning of Christmas on the winter solstice to allow converts to maintain a winter celebration, Santa Claus was regifted from Norse and Germanic traditions.

In Norse Mythology, Odin's magical eight-legged steed Sleipnir was capable of bearing him through the air and to and from the land of the dead. Odin, each winter at Yule, would launch a great hunt with fellow gods and slain warriors

Little children would stuff their boots full of carrots, straw and sugar for Odin's flying horse to eat and set them near the chimney at night. Odin, who like Santa is described as an old, bearded, mysterious man, would reward them for this kindness by leaving gifts or candy in place of Sleipnir's food.

In some European traditions (Dutch folklore) both Saint Nicolas and Odin ride white horses that can fly through the air. St. Nocolas leaves letters made of candy for the children to remind them of rune letters bestowed by Odin in Norse legend. The Durch brought this type of celebration with the Odin association to America.

Even Santa's "eight reindeer" remind us of the eight legs of Odin's wondrous steed. This particular tradition may be as easily associated with the Norse god Thor, who rode the sky in a chariot drawn by two goats, Tanngrisnir and Tanngnjóstr.