EASTER: A Damnable Heresy?

Does Easter really celebrate and honor the resurrection of Jesus Christ? Where did Easter come from? Is there any harm in celebrating Easter? If Easter, much like Christmas, is supposed to be a Christian holiday why do so many non-Christians celebrate it?

Recommended reading:
The Plain Truth About Easter:
http://www.herbert-armstrong.org/Books%20&%20Booklets/Plain%20Truth%20About%20Easter%20(1973).pdf

The Crucifixion was Not on Friday:
http://www.herbert-armstrong.org/Books%20&%20Booklets/Crucifixion%20Was%20Not%20on%20Friday%20(1968).pdf

The Resurrection was Not on Sunday:
http://www.herbert-armstrong.org/Books%20&%20Booklets/Resurrection%20Was%20Not%20on%20Sunday%20(1972).pdf