True Friendship

So here is my question:
Can we not be friends with people who don't get along with each other? Meaning; if I am friends with you and I am friends with someone you don't like does that mean that we can't be friends? 
Next question: Are we in grade school?
Last time I checked I was an adult and can make up my own mind, have my own opinions and speak to whomever I please. I wasn't aware that in order to keep some so called "friends" I had to discontinue speaking to other so called "friends" to remain the word "friends". Geesh a lot of quotation marks flying around here. 
True friendship is much like true love. You aren't going to love someone because everyone says it's wrong? 
True friendship is not passing judgment or thinking someone is stabbing you in the back while smiling to your face. True friendship is giving and taking not just always taking. True friendship is being honest enough to point out flaws in arguments or give a different perspective. 
True friendship is being there to pick someone up when they fall even when they say they are ok and to leave them alone. 
True Friendship is allowing a difference of opinion not tear you apart but allow you to see another side. It doesn't mean you believe that other way but to see it and consider it and be okay with that difference. 
I don't know about you but if everyone ALWAYS agreed with me and just told me what I wanted to hear then who do you know who is TRUE?
Don't kiss my ass and say oh yes I totally agree or understand and then walk away and do and say the opposite. Don't pretend you support me in my decisions when secretly you can't wait to see me fail. That isn't friendship that is sabotage. That is back stabbing. That is two faced. 
Don't pretend we are friends when really we aren't. Makes me feel like I am an idiot. We are all busy and have our own lives. We all have our own drama and issues. These are what makes our friends important. Don't turn your back on someone who would have been your biggest cheerleader because you couldn't take the time to be a friend. 
If it is always one party doing the talking, reaching out, and the caring eventually it will stop and you lost something that may have been just what you needed to make it through.
Be the kind of friend you want someone to be for you. Take the time and make the effort. 

Be who you are, be real, be true. I am. 

If you don't want to be my friend it's cool say so. Don't be afraid to ever tell me anything because you might lose me. You may but I would rather have honesty than someone who pretends to be something they are not.