I’m going to surprise you and say Laura Ingalls Wilder.
She has managed to write a series of children’s books that appeal to adults as well. These books demonstrate how Christianity can be lived every day, in real-life, in good times and extremely bad times.
Her book The Long Winter is absolutely inspiring, a true testimony of how God helps his people. At the end of the book, when the Ingalls family and their friends gather for a celebration meal, Pa prays, “God, we thank Thee for all Thy bounty.” This prayer is the theme of all of Wilder’s books–she recognizes that ALL that she has comes from God, and that He giveth and He taketh away, Blessed be the Lord.
Often critics analyze Wilder by saying that she seems to see life much more sharply than most of us. She doesn’t just describe a spring day or a herd of deer or a sugaring-off dance, she makes us see it. (Part of this ability on her part is due to the fact that her sister Mary went blind when she 12 due to scarlet fever–she learned to make pictures with words at a young age. Her Pa told her that she had to be Mary’s eyes, and Laura obeyed him.)
I believe that the reason Wilder appreciates life’s daily experiences so much is that she attributed all of her life and times to God. She was grateful to Him for everything, the smallest things, including a bowl of cornmeal mush, a good book, singing hymns in church with her best friend, etc.
The Christianity in these books is not in-your-face or didactic. It’s definitely there, as Wilder describes family prayers, church services, and entire hymns sung by her Pa. But it’s more a description of life as a Christian family rather than a sermon on how others should live their lives.