Coveting God (Psalm 19)

Our Lord commands us not to have a thought that would wander from His goodness.  This is a rather difficult command for us to do when we consider that our affections and desires are not set on the Lord as they ought to be set upon the Lord. So, how do we proceed in the confidence of Christ?  How do we proceed in the work of the Lord seeking to honor our Christ as His redeemed?