"If you love Me, show it by doing what I've told you."
-John 14:15 The Message
God is not petty. He is just telling me how I can show Him that I love Him.
It's like...
Whenever you get into your best friend's car and she says, "I really need to clean my car! I should clean my car." Well. I can do something about that. I love her and she is telling me a way that I can show her. So we spend some time together making her car clean and shiny.

God is doing the same thing:
"The person who knows My commandments and keeps them, that's who loves Me. And the person who loves Me will be loved by My Father, and I will love him and make Myself plain to him."
-John 14:21 The Message
"If anyone loves Me, he will carefully keep My word and My Father will love him—We'll move right into the neighborhood! Not loving Me means not keeping My words."
-John 14:23-24 The Message
I show God love by doing what He tells me, knowing and keeping His commandments and carefully keeping His Word. Sounds like a lot of work! But is it work when I am doing it to show my love for someone? I detail cars for a living. It's hard work, but doing it for my friend was not work - it was fun!
When I stop doing things because I HAVE to, and realize that when I GET to do it out of my relationship(friendship) with Him, it becomes much easier to do the things He asks me! (Also He is all-knowing and has my best interest in mind...why should I argue?!?)
When I show God that I love Him, I find that He shows me it back! He makes Himself plain, and moves right into my neighbourhood! How awesome is that? I want Him to make himself "plain" or clear, simple, honest, easy & straightforward to me. No guessing or trying to figure it out.
So when I love God, by doing what He commands, He loves me back, by showing me Who He is and what He wants for my life. What a Friend I have!!