Jesus healed a man who had suffered from an infirmity for 38 years (John 5:5). In their subsequent meeting in the temple, He challenged the man by saying, “Behold, thou art made whole: sin no more, lest a worse thing come unto thee”(5:14).
The man had suffered greatly with a physical problem for a long time, yet Jesus exhorted him concerning his not sinning any longer. Prior to this statement, the passage does not say anything about the man’s having a sin problem. Why then did Jesus challenge him in the way that He did?
Interpreters differ on the meaning of Jesus’ words to the man. Blum holds that his sin did not cause his malady:
(Stop sinning or something worse may happen to you) does not mean that his paralysis was caused by any specific sin (cf. 9:3), though all disease and death come ultimately from sin. The warning was that his tragic life of 38 years was no comparison to the doom of hell. Jesus is interested not merely in healing a person’s body. Far more important is the healing of his soul from sin.
— BKC: NT, 290; bold in original
Carson argues for the opposite view concerning the man’s sinfulness having caused his condition but agrees about what Jesus was most concerned about:
But although suffering and illness have this deep, theological connection with sin in general, and although John elsewhere insists that a specific ailment is not necessarily the result of a specific sin (9:3), there is nothing in any of this that precludes the possibility that some ailments are the direct consequence of specific sins. And that is the most natural reading of this verse. . . . If so, it is just possible John is also telling us that the reason Jesus chose this invalid out of all the others who were waiting for the waters to be stirred, was precisely because his illness, and his alone, was tied to a specific sin. . . . The something worse must be final judgment (cf. v. 29).
—The Gospel According to John, PNTC, 246; bold words are in italics in the original
Regardless of which view we take to be correct, we should keep in mind that the passage teaches that this man was healed to sin no more. From this passage, we, therefore, should learn not to allow a legitimate concern for the healing of even serious physical suffering in people to keep us from being supremely concerned about their eternal destiny.