From John Piper:

For me, the end of a year is like the end of my life. And 11:59 p.m will be like the moment of my death. The 365 days are like a miniature lifetime. And these final days are like the last hours in the hospital after the doctor has told me that the end is very near. And in these last hours, the lifetime of the year passes before my eyes and I face the inevitable question: Did I live it well? Will Jesus Christ, the righteous judge, say “Well done, good and faithful servant”?

I feel very fortunate that this is the way my year ends. And I pray that, at least for this morning, the year’s end might have the same significance for you. The reason I feel fortunate is that it is a great advantage to have a trial run at my own dying. It is a great benefit to rehearse once a year in preparation for the last scene of your life. It is a great benefit because the morning of January 1 will find most of us alive, at the brink of a whole new lifetime, able to start fresh all over again.

Teach Us to Number Our Days Teach Us to Number Our Days

The great thing about rehearsals is that they show you where your weaknesses are, where your preparation was faulty; and they leave you time to change before the real play. I suppose for some of you the thought of dying is so morbid, so gloomy, so fraught with grief and pain that you do your best to keep it out of your minds, especially during holidays. I think that is unwise and that you do yourself a great disservice. For I have found that there are few things more revolutionizing for my life than a periodic pondering of my own death. How do you get a heart of wisdom so as to know how best to live? The psalmist answers:

Thou dost sweep men away; they are like a dream, like grass which is renewed in the morning: in the morning it flourishes and withers. So teach us to number our days that we may get a heart of wisdom. (Psalm 90:5, 6, 12)

Numbering your days simply means remembering that your life is short and your dying will be soon. Great wisdom—great, life-revolutionizing wisdom—comes from periodically pondering these things.

Part of that life-changing wisdom that comes from numbering our days is humility and yieldedness to the sovereignty of God. James wrote to an arrogant group of people among the churches and said,

Come now, you who say, “Today or tomorrow we will go into such and such a town and spend a year there and trade and get gain”; whereas you do not know about tomorrow. What is your life? For you are a mist that appears for a little time and then vanishes. Instead you ought to say, “If the Lord wills, we shall live and we shall do this or that.” As it is, you boast in your arrogance. All such boasting is evil.

If we run away from the truth that we are a mist that appears a moment and then vanishes, if we try to keep this from our minds, then we will become arrogant and presumptuous. We will feel that we are the masters of our days and forget that every moment of life is owing to the free and sovereign will of God: “If the Lord wills, we shall live.”

But, if we do not run away from this truth and instead, at least once a year (for myself it must be much more often), imagine that our death is near, then we will be humbled and moved to yield ourselves to God more fully and filled with a practical wisdom for how to live.

From Desiring God
Read/Listen to the whole talk here at: http://www.desiringgod.org/resource-library/sermons/i-have-kept-the-faith