Sanctification:

Dietrich Bonhoeffer. The Cost of Discipleship. Macmillan Publishing Co., Inc.: New York. 1959.

A.W. Tozer.  Discipleship.  What It Truly Means to be a Christian. Moody Publishers: Chicago, IL. 2018

Dallas Willard. The Great Omission.  Reclaiming Jesus’s Essential Teachings on Discipleship.: HarperCollins Publishers: New York; 2006.