Monastic disciplines are not readily associated with Lutheran thought. Yet, when Philip Jacob Spener(For further information see also http://www.ccel.org/s/schaff/encyc/encyc09/htm/ii.lxxxiii.htm ,
http://www.newadvent.org/cathen/12080c.htm ) wrote Pia Desideria it was in part a reaction to the lack of discipline within the Lutheran Church.
The reality Spener confronted was to some degree a result of the focus in Lutheranism on justification by faith alone. For a variety of reasons this ended up meaning that for large numbers of Lutherans, both clergy and lay, the Christian life consisted in being baptized, memorizing the catechism and going to church but only very incidently effecting their everyday life. There was in this emphasis on justification by faith an over reaction to the perceived teaching by the Roman Church that one was saved solely by works.
Spener made what at the time was a fairly audacious claim that justification by faith not works did not contradict a call to live a disciplined and holy life. Spener opened up the possibility to speak cogently in Lutheran circles about sanctification, which one could argue is what the Orthodox and the desert Fathers and Mothers call theosis.
Sanctification is what monastic discipline is in part about. being raised by Lutheran Pietists Sanctification was a main focus of my spiritual teachers growing up. Yet, the emphasis on the disciplines of private and group Bible study are fairly limited, and individualistic, even though Spener concieved of these disciplines as corporate and not private activities, in fact activities fo the church. I wish to point out that what Spener and the Pietists were seeking to do was to reinject asceticsim into the life of Lutheranism. However, it is my experience that latter Pietists (including those in my tradition) were sudduced by a highly individualized understanding of piety and ascetisism. The other is that if we are concerned for the lively spiritual life of Christians (that is sactification) than we are in someway interested in the monastic tradition and are in fact talking about theosis.
Spener was seeking to bring balance to the emphasis Luther had due to the abuses of the practices of Roman Catholicism and monasticsim of his time. In a sense I think Geroges Florovsky's comments on Luther here are iluminating and helpful:
"It must be strongly emphasized that Luther does indeed protect one aspect of salvation, the very cause and source of redemption and grace. But he neglects the other side, the aspect of man’s participation in this free gift of Divine initiative and grace. Luther fears any resurgence of the Roman Catholic system of merit and indulgences, he fears any tendency which will constitute a truly Pelagian attitude, any tendency that will allow man to believe that man is the cause, the source, or the main spring of salvation. And here Luther is correct. Nygren’s Agape-Eros distinction is correct in this context, for any spirituality that omits Agape and concentrates only on Eros, on man’s striving to win God’s influence, is fundamentally non-Christian. But the issue is not that simple. Both extremes are false. God has freely willed a synergistic path-of-redemption in which man must spiritually participate. God is the actor, the cause, the initiator, the one who completes all redemptive activity. But man is the one who must spiritually respond to the free gift of grace. And in this response there is an authentic place for the spiritually of monasticism and asceticism, one which has absolutely nothing to do his the "works of the law," or with the system of merit and indulgences." (Georges Florovsky Collected works)