Betrayal is most often associated with love, though it can also happen between friends and so on. C.S. Lewis once said betrayal can happen only when there is love. Betrayal and deceit are two qualities that are abhorrent because they have a very bad effect on the other person, the relationship between them and their future. The scar of betrayal can last for a very long time. It takes a long period of time to build trust, friendship or relationship but only an uncaring, insensitive moment to betray someone. Betrayal usually involves lying, deceit and hypocrisy. A betraying friend or lover can be many times worse than an enemy. You can forgive your enemy but it is extremely difficult to forgive someone who has betrayed you. The heartaches do heal, though.
Some people view betrayal as a deliberate act and deceit as something convenient -- the latter being just a little less evil.
If you have been betrayed by someone – either a lover or a friend, the smartest thing to do is to break off all contact with the person. That can be hard – but it is usually the best choice.