Avira I have read your answer and I appreciate it- however from a Chassidic point of view- Hashem wasn’t missing anything- he was/ is perfect- but He decided He desired something else (dirah btachtonim).
As far as arrogant etc, a few of my friends who became lubavitch told me how they found it so refreshing- instead of doing Torah and mitzvos for themselves (to become the best ever, get Olam Haba, get closest to Hashem etc) they now put the focus on the other way around- what can I do to help make a dirah for Hashem?
It’s not that hard, just a change of mindset. And it feels better, and happier to be a giver than a taker (from a nefesh habehamis perspective.) it also takes away any limits you may have had before- because you’re doing it for the One you love most
As I said in a different thread, the sicha on how to serve Hashem with Emess (The Rambam s expression) is amazing and eye opening