I have been looking for information on this for three decades and cannot find much. A few years ago I found out that conversion is considered a part of Pastoral Theology not Ascetical Theology. Unfortunately, at least in English, Pastoral Theology books are practical manuals on how to run a parish, not how to bring them to conversion and into Ascetical Theology.
Ascetical Theology is simply the study of how to follow the Holy Ghost in leading people to heaven. There is nothing extraordinary in this study, because this covers what each and every Christian should be doing. In this we learn how to truly pray from the heart. “They have laid it waste, and it hath mourned for me. With desolation is all the land made desolate; because there is none that considereth in the heart.”[Jeremias (Jeremiah) 12:11]
“This people honoureth me with their lips: but their heart is far from me.” [Matthew 15:8] Ascetical Theology is the study of how to change this, first in our own selves as Spiritual Directors and then in the hearts of other people.
I have found a few things on conversion and are seeking others from good Catholic sources, especially the Fathers of the Church and the other Saints. If you have ANYTHING, please send it to me.
From Treatise on the Spiritual Life on Conversion
Please help me find more.