One of the best pieces of advice I ever received from a mentor was that if I admired an author, I should read who they read. Don’t let “old books” put you off!
Case in point: I started out by admiring Elizabeth George and enjoying her books when I was a new wife. Elizabeth George quotes a lot of Elizabeth Eliot, so I started picking up more of her books (up until that time I had only read Passion and Purity). Elizabeth Eliot quotes Elizabeth Prentiss quite a bit, and so began my long love affair with the book Stepping Heavenward.
If you like Piper, read Edwards.
Any other examples you can think of?