From Ed Welch’s Depression:
…one of the first lessons God taught his people was about anxiety and trust.
When the Israelites were in the desert, food was scarce, so it was the ideal place to learn how to trust. To feed the hundreds of thousands of Israelites, God rained down a kind of bread each day (Ex.16), but he only gave enough for one day (except for the day before the Sabbath, when they were given enough for two). This established a spiritual rhythm. They did what God told them to do today, and they trusted him for tomorrow. Those who trusted in themselves and collected for more than one day found that their surplus manna turned to maggots by morning. They quickly learned that faith in the true God was the only way to live.
Undoubtedly, the first couple days were the hardest. The people woke up hungry, saw that there was no food in the tent, and handn’t yet looked outside. Would the manna be there this morning? Would God be faithful to his promises? Over time, however, they became confident. They learned that God would care for them tomorrow because he had said he would, and he had been faithful the day before.
This is the backdrop for Jesus’ words of comfort, “but seek his kingdom [today], and these things will be given to you as well [tomorrow].” Your goal is to get into a manna rhythm. Seek his grace today, be faithful to the tasks in front of you, and trust him for tomorrow. Then, when you look back and see that he was faithful, your faith will be “fed” for the next day.