Difference in Definition Between Sex & Gender

Please feel free to add your own notes and comparisons. Perhaps one day I will come back and give biblical references for my thoughts, but do not count on it.

Gender: outward expression

Sex: deeply personal, private

Gender: outward trappings, clothing, communities and customs by which to behave

Sex: requires surgery or mutilation to change; can be deformed at/before birth or later in life. Always painful to change - there is blood. 

Gender: changes by stepping into the closet, so to say. Acting. Clothing, the requirements for which may change from year to year.

I give no ruling to say that this is an absolute. But I do say clearly that there is a difference between the two, and the fact of sex and the notion of gender are mutually exclusive, though they do often correspond. But that is a different subject.