In a nut shell:
The Old Testament says.... He's coming.
The Gospels tell us....... He's here.
Revelations tells us...... He's coming again.
And if it would identify itself by name it might be more respected, even. Instead its followers just come preaching out of the blue. Even Jehovah's Witnesses and Scientologists will tell you that they are Jehovah's Witnesses and Scientologists. They might be wrong but they aren't ashamed of the name of their following.
e-s and similar folks are asking too little, not too much, of Christians. As I pointed out some time back, Christ is seen everywhere in the bible. Trying to tie Him to a delineated handful of celebrations is to empester the gospel.
In a nut shell:
The Old Testament says.... He's coming.
The Gospels tell us....... He's here.
Revelations tells us...... He's coming again.