Saint Paisios the Athonite was asked by certain final year students of Athoniada on what they should pay more attention to in their life, and he responded:
Be careful in your lives of the every day small events.
You comfortably sit in your armchair and think that this is neither bad nor a sin, and you say, "it doesn't matter."
It doesn't matter if we eat something more or to ask for good food.
It doesn't matter if we sleep a little more.
It doesn't matter if we speak a little more abruptly to parents or someone else.
This doesn't matter, that doesn't matter.
We see everything as small wrongs and we justify them. But if we don't pay attention to small things then we will do greater wrongs, and again we will say: "It doesn't matter."
Let us not relax our body because this will affect the spirit. There must be watchfulness.
Source: Ο ΓΕΡΟΝΤΑΣ ΠΑΪΣΙΟΣ, ΩΣ ΝΕΟΣ ΒΟΗΘΩΝΤΑΣ ΤΟΥΣ ΝΕΟΥΣ, εκδ. «ΕΝΩΜΕΝΗ ΡΩΜΙΟΣΥΝΗ», ΘΕΣΣΑΛΟΝΙΚΗ 2010, σ. 104. Translation by John Sanidopoulos.