There are two kinds of friendship: the beneficial friendship and the erroneous friendship. The erroneous friendship balances on the principle of "the closer we are, the more okay it is for me to say anything I want to you and for me to treat you any way that I want to, and for me to disrespect you and take advantage of you" while a true friendship is rooted in this principle: "the closer we are, the more respect I have for you, the better I will treat you, the higher I will regard you, the more good things I will wish for you." You will know someone is a true friend by basis of observing their actions towards you as the friendship grows deeper. A true friend will continue to hold you in higher and higher regard while the error of a friend will see your goodwill and newfound fondness as basis to do and say whatever he/she wants, that is disrespectful and non-beneficial to you.