There are no empty people. When a human puts nothing into there lives, or their heart or mind, they are simply an open vessel, prone to be filled with all the meaningless fluff the world itself is filled with. When I do not intentionally channel, filter, and choose what goes into my mind and my heart, I am unwittingly open to all the philosophies, values, fantasies, and priorities that our lost world is producing in its' lame and futile effort to find meaning and freedom.
I have experienced this often. It is easy to say we will change our behavior, that we will be more loving, that we will be more Christlike. But it does not happen based on good intentions - I am learning more and more that if I want to really live out God's high calling on my life, I must be filling myself with His presence and the Word of God. Otherwise I am stuck - on the one hand I know my shortcomings and sin, but on the other hand I face my perpetual inclination towards the meaningless stuff that the world values, the stuff that holds my attention and fills my heart if I do not fill myself with Christ.
So, as I have read repeatedly in Proverbs lately, the key is a disciplined life. Proverbs 5:23 says, "The fool will die from lack of discipline, lead astray by his own great folly." We are all such a one when we are not pursuing the wisdom of God, but blithely letting ourselves be filled by the world. But what of the man who fills himself with God? Psalm 1 talks about the result:
2 But his (the blessed man) delight is in the law of the LORD,
and on his law he meditates day and night.
3 He is like a tree planted by streams of water,
which yields its fruit in season
and whose leaf does not wither.
Whatever he does prospers.