Law 2 of 48 laws of power by Robert greene
He has pointed out so wisely a harsh truth, which we all deny, especially those who have a huge heart, noble soul. Sometimes our friends hasten our fall, because they know a lot more about our weaknesses than our enemies, so if they become jealous or change their heart they can cause destruction, absolute destruction.
When you are showing generosity to an enemy you may earn gratitude from heart no matter how little it is, on the other hand when you are showing generosity to a friend he or she may take it as a right, and hope for more.
If we look around and search history we will see too many examples of powerful people being destroyed by closest friends, relations.
How many examples do you want?
The simple truth is proximity of a very lucky person can generate destructive envy, so better watch out!