"Conversion may be a seemingly/relatively instant event, but it does not bring with it all the values, attitudes, and habits which render the ideal practically possible. Normally years intervene while the convert tries to become what he is. The same is true of prayer; after the initial fireworks, decades of plodding fidelity follow before prayer becomes instinctual. A contemplative, as Bernard of Clairvaux reminds us, is not merely one for whom to live is Christ, but one for whom this has been the case for a long time. The practical effect of this is that a monk has to endure living with his own patent imperfections, even though he desires nothing more than to be quit of them.
An associated source of difficulty can be found in the intrinsic changeableness of spiritual life. This theme, addressed under the headings of alternatio and vicissitudo, is one of Bernard's most characteristic emphases. Life can be difficult simply because as soon as we develop skills to handle one set of circumstances, everything changes, our aptitudes become irrelevant and we are confronted with new and fearsome challenges. The temptation is either to stop trying altogether or to go back to doing the things which used to work, blocking from our mind the thought that such wooden 'fidelity' seems to be accomplishing little. It seems to be part of God's pedagogy for the monk that he is always left wrong-footed; he is not allowed to save himself, no matter how desperately he desires it." - Michael Casey, ocso