From The Richness of Ordinary Life, a homily by St. Josemaría Escrivá.
... Certainly our goal is both lofty and difficult to attain. But please do not forget that people are not born holy. Holiness is forged through a constant interplay of God's grace and the correspondence of man. As one of the early Christian writers [St. Mark the Hermit] says, referring to union with God, "Everything that grows begins small. It is by constant and progressive feeding that it gradually grows big." So I say to you, if you want to become a thorough-going Christian -- and I know you are willing, even though you often find it difficult to conquer yourself or to keep climbing upwards with this poor body of ours -- then you will have to be very attentive to the minutest of details, for the holiness that our Lord demands of you is to be achieved by carrying out with love of God your work and your daily duties, and these will almost always consist of small realities.