I don’t agree middlepath. I think it’s a much higher level to do a mitzvah because Hashem told you, even before learning the ‘reason’. And i don;t think Hashem waants it to become second nature because i just learned that one of Rabbi Miller’s 10 steps to greatness is: to think in your head b4 u do a mitzvah that you’re accustomed to doing (ex. netilat yadayim)
“I am doing this because Hashem asked me to and i love Him and want to get close to Him by listening”
Mitzvot should NOT become habit, if they do then you wont be fullfilling the main purpose of mitzvot which is to get you close to Hashem! it will just be second nature and won’t help with your connection to Hashem