Grace to endure
Corrie Ten Boom described how the grace to die well arrives---on time, not before. She wondered, will I be able to endure the torture? And her dad said, "When you take the train do I give you the ticket three weeks ahead or do I give you the ticket when you get on the train?" And she said, "When I get on the train." Well, God has a grace for you for your torture. He'll give it to you when the torture comes."
I think that's very biblical because there's a correlation of Matthew 6:34 and Lamentations 3:23. "Therefore do not be anxious about tomorrow, for tomorrow will be anxious for itself. Sufficient for the day is its own trouble." "His mercies are new every morning." So everyday has its appointed trouble, including the day of your death, and every day has its appointed mercies for those troubles, no more. If you reach forward and bring tomorrow's troubles into today and say, Lord, give me the grace for tomorrow's troubles, he'll say, I will give you the grace for that tomorrow. But you have to have a mighty deep confidence that God's going to come through for you, and that's what faith is, I believe. And that's why we go to the Word.
John Piper