Matthew 33 is an important verse that can be found throughout all of Christ’s teaching. With many beautiful examples, Jesus illustrates that when our foremost attention is towards providing for our own, temporary needs and necessities of life, it leads to fretting, worrying, and anxiety. He says that whether it be the birds or the flowers, they do not worry about where their next meal is coming from or what they will wear because the Lord graciously provides for all of their needs.
However, just like every other teaching that Christ gave, this one needs also to be understood in the light of the verses that came before it. Too frequently, the words of Jesus in this passage have been misinterpreted to imply that God will provide everything for his followers if they seek him first. But the meaning of these words does not refer to that at all.
Things like food and clothing are the basic needs of life. Jesus has instructed his followers to not live in constant worry about how they will acquire those things, even if they have no idea where their next meal is going to come from. He encourages them to set their primary focus on pursuing the kingdom of God and His Righteousness. This means to live a life abstaining from sin and to lead a sincere life with a true heart, like God, devoted to the work and not to the result. For your devoted deeds, God will provide for you with everything that is needed to live a good life.