Here is a great teaching on Gelassenheit.

The German radical reformers had a concept called gelassenheit: “yieldedness, letting be, or submission to the will of God; a sense of let-go-ness”.

While there are some English attempts at translation -abandon or surrender -, these concepts are are too dramatic. “I will abandon all for Christ”, ‘I will surrender”. So although there is some idea of gelassenheit in abandon and surrender, gelassenheit is more of “just letting go”; resting in God. There is no self credit for our abandoning all or our surrendering all to Christ because gelassenheit embodies a lack of self effort.  The Anabaptist would say that this should be our attitude; towards all gaining and maintaining; towards our very life itself. Its the abandoning of all self-affirmation, self-confidence, self-concern; “Jesus is at the center and I have a let-go-ness about everything else.”

Therefore I tell you, do not worry about your life, what you will eat or drink, or about your body, what you will wear. Isn’t there more to life than food and more to the body than clothing? Look at the birds in the sky: They do not sow, or reap, or gather into barns, yet your heavenly Father feeds them. Aren’t you more valuable than they are? And which of you by worrying can add even one hour to his life? Why do you worry about clothing? Think about how the flowers of the field grow; they do not work or spin. Yet I tell you that not even Solomon in all his glory was clothed like one of these! And if this is how God clothes the wild grass, which is here today and tomorrow is tossed into the fire to heat the oven, won’t he clothe you even more, you people of little faith? So then, don’t worry saying, ‘What will we eat?’ or ‘What will we drink?’ or ‘What will we wear?’ For the unconverted pursue these things, and your heavenly Father knows that you need them. But above all pursue his kingdom and righteousness, and all these things will be given to you as well. So then, do not worry about tomorrow, for tomorrow will worry about itself. Today has enough trouble of its own.

So, I encourage you to have and develop a sense of gelassenheit or in the words of a famous song, “Don’t worry, be happy.”