discontentment

I read this quote today in my Bible study book by John Piper (Battling Unbelief: Defeating Sin with Superior Pleasure, ch.9 Battling the Unbelief of Coventousness):

"Coveting is desiring anything other than God in a way that betrays a loss of contentment and satisfaction in Him. Covetousness is a heart divided between two gods."

Just lately I have been noticing my discontented heart...wanting life to be comfortable and easy...although nowhere in the Bible does God promise easy lives for Christians. And honestly it's not that I have a really hard life either. And yet I still think that if I had all the things that I wanted, it would somehow bring satisfaction? I'm realizing more and more my unbelief that God really does bring the ultimate/supreme/REAL satisfaction in life...my mind knows it but yet my heart doesn't always believe it.

And why does this discontentment creep up now and then? Because I am living for myself...instead of existing:

"to spread a passion for the supremacy of God in all things for the joy of all peoples through Jesus Christ." (John Pipers mission statement)

If this is truly how I live then true contentedness/joy would follow because God did/will/would provide everything I need - and I would never doubt that there was something I was lacking.