1) And don't forget the Crusades, manifest destiny, slavery, the Spanish Inquisition, the extermination of the Arawak indians, and most indigenous cultures in central and south America, and all the other things which people have done in the name of Christ.
2) And don't forget that Christ was not actually born on Christmas Day, but sometime in the fall. The holiday we celebrate as Christmas was chosen in order to merge it with pagan rites which were popular at the time.
3) And don't forget that Christmas today is more a sales tool than it is a true celebration of the birth of Christ.
4) And finally, don't forget, that true believers in Christ would celebrate each and every day of the year celebrating Christ, which means loving their neighbors, which most professed Christians do not do.
Fact is, Christ himself said that, before he returns, there would be a great falling away from the faith, in which the Son of Perdition would be revealed.
The celebration of the birth of Christ, and also his resurrection, should be constant and ongoing, not done just one or two days out of the year so that hypocrites can tell others how religious they are. And, as Christ himself said, there is a place in hell reserved especially for hypocrites.