How To Avoid A Person Who Talks Sweet On Your Face And Yet Does Back Bitting?

Depends on your situation.

If this person is a co-worker, you'll have no choice but to interact with them. (Same thing with a family member). Most others you should be able to avoid.

However, human beings are usually focused on self-preservation. So if back biting you serves their desire to boost their social status, or allow them to get ahead at work,....chances are they're going to do that.
And that strategy can be used by anybody. (So anyone can turn on you at any time it's convenient for them. Even the apostle Peter betrayed Christ when it served his purposes).

Just realize that no human being is perfect, and when someone does back bite you again (it will happen again), just don't let it make you bitter. It's just human nature at work.

Hope that helps.
I wish you good luck,and God-speed.

Confront them. Go up to them and say 'I know your a hypocrite, and I don't want anything to do with you anymore, so please stop your foolish backbiting.' Forgive them, but make sure they know you are not their friend and you will not talk to them or help them unless it is absolutely necessary. Also, remember that their stupid backbiting is nothing but a load of gossip and lies, and it's to trivial to bother about.If they backbite you in future, just ignore them - they are an idiot.

If they are back biting that means that they do not have the heart to say it to your face and they are most likely putting up a front for their friends. Most of the time people like this are just jealous these people are called haters these people hate you because you are better and you should take it as a complement. When you deal with haters just brush them off they are nothing. Hence the term,"brush them haters off" These people are best ignored if they do not say anything to your face just save yourself the headache they are not worth your brain using up energy to process thoughts you might have about them and worry about more important stuff. However if you have to or if you decide that you want to confront this person isolate them first because they wont have their friends around to put a front up. It depends on the situation whether confronting the person is would be beneficial or not. If you are not scared of this person and you can handle yourself in a physical altercation or if you know how to avoid the physical part without loosing face then it would be good to bite back, but at an angle not directly. OR you can do it directly and while this person is doing all the back biting you can be planning out a comedy central roast on her in front of everyone so you can humiliate her. Or you can figure out how to use her to your benefit or for your amusement. OR.... You can turn her into a friend and she will be your most loyal friend I read this in 48 laws of power some general or king had problems with an enemy and instead of killing this enemy he turned this enemy into a friend by using kindness and generosity and the enemy did not expect this at all the enemy became his most loyal friends. OR just avoid this person all together just "cut them off" they are not worthy of your friendship but it is not necessary to "burn the bridge" because even people like this can be useful sometimes. OR just don't act like you don't like her and don't act like you like her. OR you can mirror them. When you associate with her act like her. When you mirror someone it drives them nuts because they do not know what you are up to and they do not know your strategy. This creates a fear of the unknown in them. Either way everything depends on the situation and your values and skills and how you are as a person, but whatever you decide to do, do it without anger or violence unless you are defending yourself.