In Chapter 7 of Katharine's Yesterday, she receives a Christmas present from one of her summer friends:

“Katharine opened one small, thin package, neatly wrapped in white paper, and addressed in a bold, clear hand. Then she gave her undivided attention to the package, and to the letter accompanying it. The opened paper disclosed a small white-clad book with gold letters. The Greatest Thing In The World was the title. On the flyleaf was written, ” A Merry Christmas and Joyful New Year, from your friend, Frank Warner.” Katharine’s cheeks flushed and a pleased look came into her eyes as she turned to the letter. It read:

My dear friend,
The accompanying little book has helped me very much, and I pass it on to you in the hope that you will enjoy it as much as I have. It is Professor Drummond’s address on that wonderful love chapter, I Cor. 13. You will notice that he asks all who will to read that chapter every day for three months. I have begun to do so. Will you join me in it for the first three months of the new year? And may the greatest, the best thing in all the world be yours, is the wish of your friend,

Frank Warner

The next Sunday afternoon the new book was brought out and read; and not only the sister, but the brother, joined the young man in reading that marvelous chapter every day. Assisted by Professor Drummond’s clear, helpful words, they studied Paul’s analysis of “love”, and tried to measure their own lives by it, and alter them so that they would fit the perfect pattern.

In the short story, Some Carols for the Lord, the church young people decided that instead of having that same old children's Christmas Party they would do something different.

“It came to the houses of the rich, as well as the poor, this story sweet and old. There had been no respecting of persons that day. There were dainty cards with sprays of lovely flowers or bits of landscape and a sweet Bible verse for some, and there were a few copies of Professor Drummond’s little white book, left where it was thought they might do good.”