I've always referred to them as first name and surname. As for the origins certainly some people have Christian based names (Joshua, Issac, Mary and the names of the disciples are famous) but equally other cultures and regions have had a major influence in the commonly used names.
For all those who are curious the Dictionary defines a ............"
Christian Name" a Name given to an individual that distinguishes him or her from other members of the same family and is used as an address of familiarity a forename given generally one given at BAPTISM
Well I did have a baptism at age 3 months , obviously do not remember it nor consented to it
But I was given my name at BIRTH . way before that . its on my Birth Certificate ...I was a Preemie and hospitalized from birth to 3 months weighed 3 lbs at birth Theresa means "Reaper" or "Harvester" a Greek origin , some sites say Spanish
and out of curiosity the purpose of the question ?
why is it relevant to Atheist many atheist were once theist . but then we LEARNED to QUESTION .