Abide in Christ by Andrew Murray (first published in 1864, and regularly ever since) is 31 readings on how we can abide in Christ.
Online book: https://files.tyndale.com/thpdata/firstchapters/978-1-64158-224-7.pdf
Audio: https://librivox.org/abide-in-christ-by-andrew-murray/
(I have some notes and highlights in Google Play.)
