Kabalistic reason mirroring the creation of the world. 7 x 7000 year cycles till the great jubilee. Ramban and Abarbanel. Preface on Tiferet Yisrael. Maseket Sanhedrin.
Increase bitachon in Hashem.
Increase ‘vatranut’-forgive and forget.
Shows that G-d is the master of the world. He has the power to start or stop creation. Sefer Hahinuch
To increase one's feeling of mercy to others.
It's good for the ground and the fruits. (Rambam)
Windows to open up our blindness by the materialism around us.
To remove a person from their daily routine. Perfection and not work is the purpose of the world. What is the purpose of all the struggles when in the end everything becomes ‘hefker’. A person should make do with a little.
We are not the masters of our property, G-d is. (Rabeinu Behayeh)