Is Christmas Christian?

This is information I looked at from the Stewarton Bible School in Scotland - http://atschool.eduweb.co.uk/sbs777/vital/xmas.html

The answer most people would say to the question is "Yes, of course." But not according to these guys.

There are six reasons why they believe it is not.

(1) Christmas is a pagan not a Christian festival.
(2) December 25 was celebrated in ancient days as the birthday of the unconquerable sun god variously know as Tammuz, Mithra, Saturn, Adonis, and Baal centuries before Jesus Christ (AS) was born in Bethlehem.
(3) Nowhere in the Bible are believers in the God of Abraham, the God of Isaac, and the God of Jacob required to celebrate or observe Christmas.
(4) The early Christian church did not celebrate Christmas. Instead it celebrated the sacred festivals mentioned in the Bible, in Leviticus 23.
(5) In order to win Gentile converts to the Christian faith, the Roman Catholic Church, centuries after the apostolic era, adopted this ancient winter festival of the sun god and renamed it 'Christmas' mistakenly thinking that it would honor the Son of God.
(6) Scholars have for centuries known these facts. They can be confirmed in any reference library.

And besides this, it is researched that Christ was born around the autumn time, around late September/early October, instead of Dec. 25. This is based on their research at the Stewarton Bible School in Scotland.

Peace. Assalaam.