what does the bible say?

Christ said in Matthew 5:29-30: “And 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 [Gehenna].  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 [Gehenna].”

Christ did not intend this instruction be taken literally. The eye, the hand, or the foot cannot sin by themselves.  A person who is totally blind or is missing a hand or a foot can still sin.  Sin is conceived in the mind.  

In James 1:14-15 it states: “But each one is tempted when he is drawn away by his own desires and enticed.  Then, when desire has conceived, it gives birth to sin; and sin, when it is full-grown, brings forth death.”  That is why we are to bring “every thought into captivity to the obedience of Christ (2 Corinthians 10:5).

Jesus was simply using parts of the body to illustrate an important principle.  He was explaining that a Christian should strive to remove sin from his or her life; and that one must eliminate a sinful habit even though the process may be as painful as losing an eye, arm, or a leg.  The point Jesus was making is it would be far better to give up a sinful pleasure than to lose out on eternal life (1 Corinthians 6:9-10; Revelation 21:8).