Why is "Good Friday" called "good", instead of sad or bad? [closed]

This Friday (Good Friday, April 22) is a day of sadness to the human kind. Then, why is it called Good Friday?


The Wikipedia page on Good Friday reports the following:

from the now obsolete senses pious, holy of the word "good."

So, good can be traced back to meaning holy, which then gives more sense to the expression.