Grasping for Contentment

Why does contentment often feel like trying to hold water in my hands?  The muscles in my fingers weaken and drops start to sneak out.  And then there are the times when I throw the whole bunch down in frustration.  A moment passes, maybe a day or a week, and then I reach into the bucket of His Word and prayer and get a new handful, begging Him to be the strength my muscles need to keep holding that water.  I've noticed something about this struggle, this casting out and scooping back up.  When my eyes are up, the muscles hold, when my eyes are on the world, on my circumstances, on the temporary, that's when the drops start falling.  So why can't I just keep  my eyes up?  What pulls them down?  Oh promises of the world, you render me weak!  Why is it so hard to believe the truth that this life is but a breath, that experiences and things and accomplishments by the world's standards mean nothing?  The "Screwtape Letters" post daily, the ways in which the evil one would drag my heart away from what is true and good and meaningful.  The lies on the tip of the serpents tongue hissing that my life is about me when deep in my heart I know the beautiful truth that it's ALL about and by and for Him!  Oh precious Words from the Maker of all, fill my heart and mind and memory!  Fight for me Daddy, hold up my hands, push my fingers together, for I am weak...