Love and Enmity for the Sake of Allah Only
Another example of this is Prophet Loot (A.S.). He fled his city by Allah's command, and tried to save his family, but this was not the will of Allah, for his wife was not of the believers.
"But we saved him and his family, except his wife: she was of those who lagged behind" (7:83)
Here we see that Allah did not save the wife of the Prophet. He had to choose between obeying Allah and saving his wife, he had no choice, he obeyed Allah. He knew that the only relationships that exist are those for the sake of Allah - seeking His Great Pleasure.
Rasulullah (Sallallahu Alaihi Wasallam) said:
“A person visited his brother in another town and Allah deputed an Angel to wait for him on his way and when he came to him he said: 'Where do you intend to go?' He said: 'I intend to go to my brother in this town.' He said: 'Have you done any favour to him (the repayment of which you intend to get)?' He said: 'No, except that I love him for the sake of Allah, the Exalted and Glorious.' Thereupon he said: 'I am a Messenger to you from Allah (to inform you) that Allah loves you as you love him (for His sake).'” (Sahih Muslim: Book 31, Number 6226)