What is the concept of love in the Qur'an?

In societies which do not live according to the moral values of the Qur’an, very different values can cause people to feel love and respect towards each other, like sharing the same culture, holding a title, being beautiful, or dressing smartly. A love based on such worldly values is not, of course, true love at all. And such respect is not true respect. Once the other side no longer possesses these means, the love they maintained was so powerful will disappear in a single moment. Yet, the real goal of the believers is the approval of Allah. Because of their love for Allah, they also feel love and affection towards that which Allah created. This love never fades in the face of want or difficulty and is not shaped by material values. They are never on friendly terms with manners with which Allah is not pleased, nor can they feel any affection towards a person embodying such manners in their hearts. This is stated in the Qur’an:

You will not find people who believe in Allah and the Last Day having any regard for anyone who opposes Allah and His Messenger, though they be their fathers, their sons, their brothers or their nearest kindred.  (Surat al-Mujadilah, 22)

What is the concept of love in the Qur'an?