why do people say merry christmas

People say "Merry Christmas" because it's a tradition to greet each other with a message of joy and goodwill during the holiday season. It's a way to spread cheer and wish each other happiness during a time of year that's often filled with stress and busyness. The phrase "Merry Christmas" is used to express feelings of joy, gratitude, and togetherness, and it has become a staple of the holiday season.