Abu Hurairah (May Allah be pleased with him) reported: Messenger of Allah (PBUH) said, "Allah, the Exalted, has said: `I will declare war against him who treats with hostility a pious worshipper of Mine. And the most beloved thing with which My slave comes nearer to Me, is what I have enjoined upon him; and My slave keeps on coming closer to Me through performing Nawafil (voluntary prayers or doing extra deeds besides what is obligatory) until I love him, (so much so that) I become his hearing with which he hears, and his sight with which he sees, and his hand with which he strikes, and his leg with which he walks; and if he asks Me something, I will surely give him, and if he seeks My Protection (refuge), I will surely protect him".
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].