What does it mean that 'sufficient unto the day is the evil thereof' in Matthew 6:34'?

TL;DR:

Remembering that "sufficient unto the day is the evil thereof," calls us to trust in God in the midst of life’s difficulties. Worrying cannot change our circumstances.

The expression "sufficient unto the day is the evil thereof" is a biblical adage found in the Sermon on the Mount. The full verse reads, "Take therefore no thought for the morrow: for the morrow shall take thought for the things of itself. Sufficient unto the day is the evil thereof" (Matthew 6:34, KJV). The ESV of this verse reads this way: “Therefore do not be anxious about tomorrow, for tomorrow will be anxious for itself. Sufficient for the day is its own trouble.” In other words, we should concentrate on present-day troubles because today has enough worries of its own. In contrast, worrying does not accomplish anything. We cannot change our circumstances through worrying, nor can we add years to our lives. So, instead of worrying, we are called to trust in Him who works all things together for the good of those who love Him (Romans 8:28–29).

from the old testament

We do not know what tomorrow holds, but we know the One who holds tomorrow in His hands (Jeremiah 29:11; Psalm 23).
Psalm 55:2 says, “Cast your burden on the LORD, and he will sustain you.”
In Psalm 27:4 David wrote, “One thing have I asked of the LORD, that will I seek after: that I may dwell in the house of the LORD all the days of my life, to gaze upon the beauty of the LORD and to inquire in his temple.” In this psalm he also prayed for God’s intervention in his circumstances. In David’s prayer we see an example of seeking God and His kingdom first, and then trusting Him for our material needs.

from the new testament

In Matthew 6:24, Jesus addresses the issue of divided loyalty in His Sermon on the Mount. It is impossible to serve two masters simultaneously because we will love one and hate the other, or be more devoted to one than the other. Thus, we are faced with a choice: will we serve God or trust in something else like money?
In Matthew 6:25, Jesus commands His disciples to not become anxious about material needs, such as food, drink, and clothing, because life is more than these things (cf. Matthew 4:4; John 4:13–14; 6:48–50).
In Matthew 6:26–30, Jesus presents an argument against worry. If our Heavenly Father feeds the birds of the air, then He will do the same for us (Matthew 6:26). And if He clothes the lilies of the field, then He will certainly put clothes on our backs (Matthew 6:28). To think that God would do these things for plants and animals and leave His children without is to have a shameful opinion of Him. Indeed, it displays a lack of faith (Matthew 6:30).
The more we understand our value before God and comprehend how much He loves and cares for us, the less we will worry (cf. 1 Peter 5:7).
Worrying does not accomplish anything (Matthew 6:27). We cannot change our circumstances through worrying, nor can we add years to our lives. So, instead of worrying, let us trust in Him who works all things together for the good of those who love Him (Romans 8:28).
In Matthew 6:31–32, Jesus reinforces the command to let go of worry and anxiety about material needs. The Gentiles (or unbelievers) seek after these things, but our Father is aware of our needs and will take care to provide for us.
In thanking the Philippian church for a gift, Paul told them, "God will supply every need of yours according to his riches in glory in Christ Jesus" (Philippians 4:19).

implications for today

In Matthew 6:33, Jesus establishes the top priority for all believers: we should devote our lives to doing the will of God (Philippians 4:8) rather than being preoccupied with money, food, and clothing. We can do this because of who God is and how He loves us. In Matthew 6:34, Jesus reminds believers to live in the present rather than worrying about tomorrow, because "sufficient for the day is its own trouble." When Jesus said, "Sufficient unto the day is the evil thereof," He was pointing out a fact of human existence. In a fallen world, every day has more than enough trouble of its own. It is unwise to add to today's trouble by worrying about tomorrow's trouble. When we remember this we avoid the foolishness of anticipating future troubles—troubles that may not even come to pass. None of us know the future, so to worry about it is pointless. Besides, no matter how much we worry, our anxiety can never prevent trouble. Holocaust survivor Corrie ten Boom stated a related truth: "Worry does not empty tomorrow of its sorrow. It empties today of its strength" (Jesus is Victor, Fleming H. Revell Co., 1985). American Theologian Reinhold Niebuhr wrote a helpful prayer for serenity, peace, and strength to face the troubles of each day: "God grant me the serenity to accept the things I cannot change, courage to change the things I can, and the wisdom to know the difference."

understand

Sufficient unto the day is the evil thereof means that each day has enough trouble of its own.
Instead of worrying about tomorrow and adding more stress today, we are called to trust God for our tomorrow.
Worry does not change our circumstances or extend our lives; instead, we can trust that God will provide for our needs, just as He cares for the birds and flowers.

reflect

How can you shift your focus from worrying about tomorrow to being more present and trusting in God for today’s challenges?
How have you experienced God's provision in your life, especially during times when you were tempted to worry?
What steps can you take this week to actively trust God instead of succumbing to anxiety about future uncertainties?

engage

How can we balance planning for the future with not worrying about tomorrow?
What are some practical ways we can encourage each other to trust in God for both our future and daily troubles?
How does understanding God’s character and promises, and our identity as children of God, influence our ability to manage anxiety and worry in our lives?