Winter was harsh time for everyone. Even those born in warmer climates experienced the change of seasons and crops could fail if little rain fell or insects were overly populous. The life sustaining foods of nature defined the existence of early mankind and anything that threatened the survival of mankind itself. Thus winter has been a challenge to survival since the dawn of time.
Early religions, therefore, were based almost solely on pleasing whatever gods might guarantee a reprieve from the harsh punishment of the season. Gods for plants, for animals to be hunted, for plentiful rains or warm suns- all were worshiped and appeased in hopes of safe passage through the season. Though historical record came long after many religions had already died out what we do have record of indicates that most of the customs still in practice had very ancient roots.
The most ancient practice was arguable the feast- the act of consuming large amounts of food in celebration. This was done out of necessity- meats and fresh harvest fruits would not keep and needed to be eaten before rotting. A variety of different religious customs honored different gods through feasting. The Celts celebrated a full day of the winter solstice by marking the passage of the sun and oriented their societal year around the event with marriages and acknowledgements of births and deaths. The Norse Vikings burned a Yule log to symbolize the return of light after the solstice. Even the Greeks and then Romans in warmer climates celebrated the harvest with feasting and drinking.
Different customs were adapted by different people but the activities remained remarkably similar- the feast. So now when we gorge ourselves on turkey and casseroles and vegetables and pies and cookies and candies and everything else under the sun we’re actually continuing one most ancient traditions. And sure it looks a bit different, but the act hasn’t actually changed all that much in thousands of years.