As we talked, one of the principles of the Baal Shem Tov is to serve Hashem with joy.

One serves Hashem not only when praying and studying but in everything one does. Whether eating or going for a walk, one should do it with joy. Additionally, since Hashem is always with us, there is no room for worries. https://www.torahrecordings.com/rebbe/igroskodesh/011/008/3451