This is just speculation on my part, but...want to guess what Topps used as its source for finding the original artwork for these cards?
...A Christian art house?? Nope
...The Vatican?? Wrong again
So where did People of the Bible come from?
Topps used the same source that any elementary school student uses when writing a report...
They really knocked themselves out on this one. If you go to Wikipedia and do a search on the 15 people featured on the cards, for nine of them the first picture on Wikipedia is the one on the Topps card. For three others, you need to scroll down the page a little before you come to the picture Topps used. And for David, you have to go to the page for Goliath, but there you'll find the picture first.
The only two not in Wikipedia are Luke and Mary Magdalene. Finding the original for Mary Magdalene was pretty simple. Luke's, however, was not. In fact, I still haven't found the original.
Here are the cards, side by side, with the original artwork, compliments of our friends at Wikipedia.
Here's the Luke card, the one I struck out on.
I found a couple pictures that were close, but none that matched exactly. Maybe one of you will have better luck....and don't bother checking Wikipedia.