Matthew 5: 29-30 "If your right eye causes you to sin, pluck it out and cast it from you; for it is more profitable for you that one of your members perish, than for your whole body to be cast into hell. And if your right hand causes you to sin, cut it off and cast it from you; for it is more profitable for you that one of your members perish, than for your whole body to be cast into hell."
These meaning of these verses refers both to the physical body, in a sort of hyperbole fashion, and to the body of Christ (the church), in a metaphorical sense. In reference to the physical body, it is better to lose one's sight than to lose one's soul. But the message is like a hyperbole. It is spoken in exaggerated fashion to produce a desired effect and not meant to be taken literally. Literally, we are not to cut off our hand or pluck out our eye. The point is what I said a few sentences ago-- it is better to lose one's sight and go blind then to lose one's soul. If there is something which causes you to sin, then it needs to be plucked out. In other words, if something leads to sin, then that thing itself should be avoided. This may be different for every person.
On a larger scale, it also means the body of Christ, the church. If a member is in sin, then the member should be put out so as not to lead the entire body into sin. This is in line with verses in the Bible about not sitting with those who claim to be brothers, yet are living in sin. (There was a thread on the old forum about this, but it was created before this new forum came up, so it is not here.) The point is about not allowing the one bad apple to spoil the bunch.