What does Luke 12:30 mean?

Jesus is explaining that God knows His children need things like food and clothing. "Nations" refer to Gentiles—non-Jewish people—and is often used as a biblical metaphor for those who don't have a relationship with God. Jesus' followers should not act like godless unbelievers who frantically search for food and clothing so they can survive.

Among the reasons for the propagation of false gods was the need for food. From the time before Abraham, cultures created deities to which they could sacrifice to win favorable conditions for a good harvest, such as rain or fertility. The Greeks had Demeter, the goddess of the harvest, and her daughter Persephone, the goddess of vegetation. Hermes was the Greek god of husbandry. The Romans had Ceres, the Egyptians had Osiris, and the Philistines had Dagon (Judges 16:23). All the nations sought food and the wool and flax they needed for clothing, but only one God knows His children need such things. Neither pagan gods nor anxiety will fill our needs.

Jesus has spoken on this before. He pointed out that if earthly fathers know to give good gifts to their children, how much more does God the Father know how to bless His children—specifically, by giving them the Holy Spirit (Luke 11:11–13)?

Part of life is taking reasonable steps to eat, take shelter, and be clothed. Yet we should not expend all our energy trying to acquire earthly needs; we have more important things to do (Luke 12:23). We should seek God and His kingdom. In the parable of the rich fool, a man accumulated several years' worth of harvest and died that night. He wasted his efforts on something he could not keep at the cost of something he could not afford to lose. Jesus explains, "So is the one who lays up treasure for himself and is not rich toward God" (Luke 12:21). By seeking God's kingdom, not our own, we will receive an eternal reward. In addition, God will provide what we need according to His purposes (Luke 12:31–33).