No it's not!
Halloween is a Catholic feast based on the pre Christain Celtic harvest festivals - have you not heard of 'The Reformation' for the last 500 odd years Britain and other's have been joyfully moving away from the mumbo jumbo of the Catholic church and in more recent years Christainity in general, to a point a few years ago when most people in the UK cared little for the medieval doctrines of various Ancient story books.
I find it quite sad that the so called Religious leaders of the world still have so much influence in the modern world, with the middle east teetering on going back to the dark ages, and The Pope lecturing the world on 'this and that' yet doing nothing on the long term systematic child abuse by Catholic priests!
The sooner the world is free of so called religion the better ;-)
Well, you know history of England better than me.
In my view Halloween is not a Christian celebration because it is a kind of pagan harvest festival.
If a Catholic priest-or any one of us- commits iniquity he can not say anymore that he is a true Christian.
We can try to cover up our mistakes, but God sees everything that happens.
I would not be suprised if people are disillusionedwith religion and therefore Jesus must come back.