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 5:29)
Compare ch. 18:8, 9. In ch. 5:28 Christ went behind the act to call attention to the motive that prompts the act, that is, to the attitude, or frame of mind, that gives birth to the act. Here He goes behind the motive or attitude to point to the avenues by which sin gains entrance into the life, the sensory nervous system. For the majority the strongest inducements to sin are those that reach the mind by way of the optic nerve, the auditory nerve, and other sensory nerves (AA 518).
He who refuses to see, hear, taste, smell, or touch that which is suggestive of sin has gone far toward avoiding sinful thoughts. He who immediately banishes evil thoughts when, momentarily, they may flash upon his consciousness, thereby avoids the development of a habitual thought pattern that conditions the mind to commit sin when the opportunity presents itself. Christ lived a sinless life because “there was in Him nothing that responded to Satan’s sophistry” (DA 123).
It would, in one sense of the word, be better to go through this life blind or otherwise maimed than to forfeit eternal life. But Christ here uses a figure of speech. He does not call for mutilating the body, but for controlling the thoughts. To refuse to behold that which is evil is fully as effective as making oneself blind, and has the added advantage that the power of sight is retained and may be applied to things that are good.
A fox will sometimes gnaw off its own paw, held fast in a trap, in order to escape. Similarly, a lizard will sacrifice its tail, or a lobster its claw. By the plucking out of the eye or the cutting off of the hand Christ figuratively speaks of the resolute action that should be taken by the will in order to guard against evil. The Christian does well to follow the example of Job, who “made a covenant with ... [his] eyes” (Job 31:1 cf. 1 Cor. 9:27).