Abu Hurairah (May Allah be pleased with him) reported: The Prophet (PBUH) said, "When Allah loves a slave, calls out Jibril and says: `I love so-and-so; so love him'. Then Jibril loves him. After that he (Jibril) announces to the inhabitants of heavens that Allah loves so-and-so; so love him; and the inhabitants of the heavens (the angels) also love him and then make people on earth love him".
[Al-Bukhari and Muslim].

Another narration of Muslim is: Messenger of Allah, (PBUH) said: "When Allah loves a slave, He calls Jibril (Gabriel) and says: `I love so-and-so; so love him.' And then Jibril loves him. Then he (Jibril) announces in the heavens saying: Allah loves so-and-so; so love him; then the inhabitants of the heavens (the angels) also love him; and then people on earth love him. And when Allah hates a slave, He calls Jibril and says: `I hate so-and-so, so hate him.' Then Jibril also hates him. He (Jibril) then announces amongst the inhabitants of heavens: `Verily, Allah hates so-and-so, so you also hate him.' Thus they also start to hate him. Then he becomes the object of hatred on the earth also".
[Al-Bukhari and Muslim].