Mark 9:47  And if thine eye offend thee, pluck it out: it is better for thee to enter into the kingdom of God with one eye, than having two eyes to be cast into hell fire:

Matthew 5:29  And if thy right eye offend thee, pluck it out, and cast it from thee: for it is profitable for thee that one of thy members should perish, and not that thy whole body should be cast into hell.
Matthew 18:9  And if thine eye offend thee, pluck it out, and cast it from thee: it is better for thee to enter into life with one eye, rather than having two eyes to be cast into hell fire.
 
Should these words be taken literally or as figures of speech (hyperbole, figurative exaggeration)?
 
Jesus occasionally used hyperbole to make a point so memorably it could never be forgotten. (Those who study memory techniques know that an exaggerated image is far easier to remember than a normal one.)
 
However, literal-minded people, if zealous about obeying the commandments, or if oppressed by demons to carry out such a maxim literally, can not only harm themselves needlessly, but also bring repute to the whole body of believers.
 
An example occured at Viareggio near Pisa in Italy on October 3, 2011, when a 46 year old British-born Italian man gouged out his eyes in church in the middle of Sunday Mass, after hearing voices in his head telling him to do so! Church-goers were stunned. It resembled a horror film.
 
He collapsed to the floor while his mother tried to help him and the local priest rushed out to alert emergency services. An off-duty paramedic was one of those closest to him and tried to help, but to no avail. Surgeons operated on him for two hours and tried to re-insert his eyes in their sockets, but the surgery was unsuccessful, and the man will remain blind for the rest of his life.
 
What do you think an incident like this does for the reputation of Christians?
 
Two points to remember:
 
Firstly, God does not speak in voices. When He speaks, it is just one voice.
 
Secondly, look at the context of the saying, and check out whether it's hyperbole, like the phrases "strain at a gnat and swallow a camel", "it is easier for a camel to pass through the eye of a needle than for a rich man to enter the Kingdom of God".