He is based on Saint Nicholaus (literally “Saint Claus “) of Turkey, who was famous for giving gifts around christmastime. He was watered down into a secular figure to make him more palatable for non xtians.
The entire “Yule” celebration would be immediately recognizable to the modern eye as “Christmas”, in pre-Christian Europe.
My point is that Santa Clause has, at best, a tenuous link to Christianity, if it is not, in fact, a rationalization after the fact (What pagan Sinterklaas? He was a Christian saint, in.... Turkey.... yeah that is the ticket!).