Hazrat Abu Hurairah ra narrates that Prophet (Salutations and blessings of Allah SWT be upon him) said:
When Allah SWT makes someone His beloved, He calls for Hazrat Jibrael(AS) and tells him that I love so and so, you must love him also.
Hazrat Jibrael loves this individual and announces in the heavens that Allah SWT loves this person so you all must love him. Hence all beings in the heavens love this individual.
Then the acceptability and love of this person is placed in the heart of the people of Earth.
Similar is the case when Allah SWT hates someone. The abhorrence to this individual descends to the heart of the people of the Earth in a similar manner.
Explaining this hadith Hakeemul Ummat Mawlana Ashraf Ali Thanawi ra writes:
In this hadith one of the differentiating characteristic signs of Awliya (friends of Allah SWT) from non-awliya is mentioned. This sign must be used while searching for a Sheikh. It is most essential to avoid a non-acceptable individual (as a Sheikh).
(This characteristic is “being maqbool i.e. accepted by Allah SWT”.)
This means, that without any worldly reason, or any other worldly association, or hope of material profit or loss, turning of hearts favorably towards an individual and holding a good opinion about him by most of the creatures is a sign of his being loved and being accepted (by Allah SWT).
Haqiqat et tariqah min Sunnatal aneqah: At-Takashuf, page 269
The thing to note is that true acceptability comes from above downwards. That is, from elite to general public and not vice versa.