Now that Friend, besides for what He’s done for the nation on a whole, He has done everything for you too. He has equipped you with a body. He has given you a good pair of eyes and a nose and a mouth — everything! Hands and feet! All He asks of you is you shouldn’t do with them what’s wrong. You should do only what’s right. That’s all He wants of you.
Suppose you gave your fellow man an expensive machine, let’s say a computer machine. It costs maybe two thousand dollars. And you made one condition: “Don’t bang anybody over the head with the machine. It’s not good for the machine and it’s not good for your fellow man’s head. That’s all I require of you.”
So let’s say it happens that this friend is visiting and you’re busy, so you get frustrated and you take the machine and you give him a bump on the head with it.
Ohohohoh! “That’s why I gave you a machine?! To give me a bump?!”
So just like you would be very much put out if you were treated that way after you gave this man such a machine, so don’t put Hakadosh Baruch Hu out by mistreating Him when He gave you such a complicated perfect machine — that’s your body and your mind and everything else. And after all that He did for you, show some gratitude — a little bit at least — by fulfilling everything He tells you in the Torah. Every mitzvah is an expression of gratitude. You're not doing Him a favor; you’re showing gratitude for all of His favors.
