I recently received a good question.
How can Jesus say, "don't worry about what you will eat or wear” (Matt. 6:25-34), when people starve every day?
First, we must understand that Jesus powerfully understood poverty and suffering as an ongoing reality (Matt. 26:11). In fact, earlier in chapter 6 of Matthew he presumes people will continuously give to the needy (Matt. 6:1-2). This assumes that the needy will remain. The ancient world was littered with suffering and poverty, so it helps to realize that Jesus spoke considering these present realities. Jesus entered people’s suffering: He raised the dead; He fed the hungry. But He didn't raise everyone, and neither did He feed everyone. He could have, but He didn't.
It's best to understand the Sermon on the Mount as a message that speaks in generalities to make points. Not only is this good public speaking, but 1st century rabbis spoke like this to aid memory in an oral culture. What Jesus means is that we shouldn't worry about things we can't change - our height, our natural hair color, etc. (Matt. 6:27) - but we should be active in what we can change: in providing for the suffering and working to usher in the kingdom of God that Jesus promised and showed a glimpse of in His life.
The Sermon on the Mount focuses on what ultimately matters in life as we trust in God to provide for the things that don't. And generally, God does. Every day, God feeds the poor and takes care of the oppressed, and He puts it in the hearts of people to have compassion for the sick and the starving. But the Sermon on the Mount is ultimately about God and eternity, not about the world and the current state. Jesus commands us to invest in God's kingdom for the very reason that this world is full of things that fade, die, are stolen and perish (Matt. 6:19-21). Therefore, we should consider the birds of the air and the lilies of the fields as signs of God's power and goodness and yet not lose sight of the fact that the world is fallen. And because it is fallen, we should see these things as merciful realities that remind us to use our fleeting lives to focus on issues of eternal significance.
Of course, the larger question remains: "Why doesn't God provide for everyone in everything?" This is not a question anyone knows the answer to. I generally use the policy that I trust God because of what I do understand rather than reject Him for what I don't understand. But, still, there are lots of possible reasons God could have for allowing starvation even though He is all-powerful and good. Aside from the obvious (the world is cursed), the focus on the purpose of life helps to answer this question for me.
The purpose of life - if Christianity is true – is for us to know God and for God to be glorified by the spreading of His kingdom and the doing of His will (Matt. 6:9,10). These take clear precedence in the Lord's prayer over our daily provision. Therefore, it's fair to assume God might allow people to undergo suffering if it were to help the spreading of His kingdom and the doing of His will. And very often, it does. In fact, the very places where starvation and death are rampant are the places Christianity has exploded in the last century. In Africa, there were about 10 million Christian around 1900. Now there are about 350 million. In China, there were about 5 million in 1950; now there are close to 100 million. These explosions of Christian faith have come through the very evils that cause us to question God in the Western world.
The reasons for this include the reality that the West lives under a veil of modernity, which can become a curse of affluence (at least, when it comes to spiritual things). Sometimes God's blessings don't come with fully stocked fridges and paved roads; sometimes His curses do. And sometimes God's curses don't come in pains and tragedies; sometimes His blessings do. No one knew that better than Jesus, since God didn't answer Him in His greatest despair, and yet it was that moment of unanswered despair that led to His ultimate victory over death, sin, and pain.
But it comes down to this for me. A sermon isn't a science treatise or a philosophical lecture. Technically, the mustard seed isn't the smallest seed (Matt. 13:31), salt can't technically lose its saltiness (Matt. 5:13), and God doesn't technically provide for the physical needs of all His people (Matt. 6:25-34). But the point is that the Kingdom of God emerged from humble beginnings, the dilution of doctrine and practice weakens testimony, and - generally speaking - we should trust in God for the things we can't change and get busy changing the things we can.
This doesn't mean Jesus didn't speak truth. He did, if we understand Him properly. If every sermon included every qualification, we'd get very bored very quickly. And we aren't changed by treatises or science lectures; we're changed by imperatives with illustrations that drive the point home. This is what Jesus did. And He did it better than anyone.
 John Dickson, The Christ Files (Grand Rapids: Zondervan, 2005), 69.
 Philip Jenkins. The Next Christendom: The Coming of Global Christianity (Oxford University Press: New York, 2002), p. 2, 32.