This is a translation of a scriptural meditation from the Russian book, “Day by Day”. Some of Lewis’s thoughts on the subject follow:
Scripture: “Sufficient for the day is its own trouble” (Matt: 6,34)
"Do not worry in advance about your weakness, “Sufficient for the day is its own trouble”. Do not be afraid of tomorrow: tomorrow will take care of itself. Everything is possible for the One Who sent you spiritual peace today. He will not refuse to give you this peace tomorrow as well. Do not worry yourself with concerns about future trials which have not yet come. Do not yield to any concerns, do not try to see what’s ahead. Do not make any effort to guess what the future holds, but distance yourself from every fear by faith in the Lord and by hope for His timely assistance.
Submit entirely in everything to the Lord in complete faith that, together with trials, He will also send you sufficient strength to bear them, and the Lord “shall supply all your needs according to his riches in glory” (Phil: 4, 19). Give Him everything; taking up the plough, do not look back, do not dwell on details, have the courage, trusting Him in everything, to wait calmly, with complete hope and total submission, for the fulfillment of His will.
"Remember that strength is given not for tomorrow’s, but today’s, cross. There was a person who was deeply dejected, told someone about his worries, and asked: “Why is it so terribly hard for me?” – “Because”, the other person replied, - “together with the present burden you have also taken up a future one and are carrying this future part relying on your own strength, and not God’s.”
“One’s own strength oppresses through helplessness, but God’s strength elevates through omnipotence.”
This is what Lewis wrote to Mary Shelburne on May 4, 1962:
“Thank you for all your kind prayers. You have mine daily. Yes – it is sometimes hard to obey St. Paul’s ‘Rejoice’. We must try to take life moment by moment. The actual present is usually pretty tolerable, I think, if only we refrain from adding to its burden that of the past and the future. How right Our Lord is about ‘sufficient to the day’. Do even pious people in their reverence for the more radiantly divine element in His sayings, sometimes attend too little to their sheer practical common-sense?”
“Love is patient and kind. Love is not jealous or boastful or proud or rude. Love does not demand its own way. Love is not irritable, and it keeps no record of when it has been wronged. It is never glad about injustice but rejoices whenever the truth wins out. Love never gives up, never loses faith, is always hopeful, and endures through every circumstance. Love will last forever.” (1 Corinthians 13: 4-8)