The Prophet Sal Allaahu Alayhi wa Sallam said,
"When Allah Subhaanahu wa Ta'Aala loves someone he calls to Jibreel saying,
"O Jibreel, I love such and such a person so love him."
Then Jibreel will call to the (angels) of the heavens,
"Allah loves such and such a person so love him."
And the angels will love him.
And then Allah Subhaanahu wa Ta'Aala will place acceptance on earth for that Mu'min."
{Bukhari and Muslim}