Enemies aren’t half as dangerous as loved ones!!!

I read an article yesterday and the gist of it were the two sentences below.
Enemies aren’t half as dangerous as loved ones today, because people closest to our hearts are the ones who are selling us out
Be nice to all, friends with few and trust only one… you!
If this is really the state of affairs, then it is a very sad situation. Well I don't believe it is true broadly speaking, though these of incidents do happen as we hear about. One aspect to think about is why do these people get-together in the first place. While I am not running down the affected people, I do think that people have become more superficial these days and neither have the time or inclination to invest time in relationships and even personal relationships are based on need, convenience and possibly some expectations. In that case even all relationships become businesslike in nature and selling out for profit is part of the game. So people can't complain about selling out. If you have your heart and mind at the right place, then you will have the right people around you, this won't happen.
About the second statement, I can't disagree with the last part more. If you can only trust yourself and no one else, then I think there would be no growth for you either in your personal or professional life.