Discontent is one of life's most corrosive vices. When we wish we lived then, when we want our life to be taking place over there, we take no joy in what's here and the now. We cannot enjoy the present without receiving it, and we cannot receive it well unless we receive it gratefully.All of life must be seen as the gracious gift of God that it in fact is. When things aren't going according to our plan, it is beneficial for us to remember and to be thankful that it is going according to God's plan. To live the good life, the content, peaceful, joyful life, one must receive all of life and all that comes with a thankful heart.
Leithart's thoughts can be found here. His recent theological study on this all too neglected topic may be found here.