Wholeheartedness is the key
Hashem adjures us to ‘cleave to Him’ - and as Hashem is upright and righteous, one who wants to cleave to Him, has to also be ‘upright and righteous’.
Hashem adjures us to ‘cleave to Him’ - and as Hashem is upright and righteous, one who wants to cleave to Him, has to also be ‘upright and righteous’.