I am becoming increasingly convinced, as I get older, that God does not demand our obedience simply because it honors Him. That is, of course, a true and healthy reason to do it. And I wouldn’t even put up an argument against someone who argues that it’s the primary reason.
Still, as I come to experience and better understand God’s love for us, I’d suggest that God demands our obedience because He desires us to become the people we were truly created to be. Because only God sees the final picture, He is therefore the only one capable of making it happen. Therefore, without our obedience — our submission to God’s vision of us, which is far bigger than any vision we could come up with — the end result is a tragedy that only God can comprehend and experience the full depths of. The suffering we see and experience is but a rough fragment of that.
By extension, I think that’s why Jesus became so angry with the Pharisees. They saw a broken law as an excuse to claim superiority. Jesus saw it as a sin so profound that only He could die to remove it.
Joy and longing are not always related to one another. The joy produced by longing also delivers the promise of fulfilment, while longing without joy usually evolves into depression, decadence or both, depending on your moral inclination. It is the joy, not the longing, that should be desired.