The purpose of human existence is to prepare the world for redemption so that it will serve as a dwelling place for God, “and all flesh will see together that the mouth of the Lord has spoken” (Isa. 40:5).
Every good deed brings the redemption closer, and the performance of every mitzva repairs the world on some level.
However, when a person is faced with the overarching purpose of existence, namely, to rectify completely the entire world, there is significance not only in that someone made a repair, but also in the size of the repair, determined by the
scope and power of the deed.
A mitzva performed only with one’s body has a limited scope.
But when a person harnesses his power of thought, attaching his soul to the mitzva and to the One commanding it, the mitzva receives immeasurably greater intensity and scope.
Rabbi Adin Steinsaltz