In John 5 Jesus heals a man who has been by the pool of Bethesday for 38 years without any healing of any kind. After healing this man Jesus turns to him and tells him to “sin no more, lest a worse thing come to thee.” Albert Barnes does a very good job explaining just what the phrase “sin no more” meant in relation to the context and his comments are below.
By this expression it was implied that the infirmity of this man was caused by sin – perhaps by vice in his youth. His crime or dissipation had brought on him this long and distressing affliction. Jesus shows him that he knew the cause of his sickness, and takes occasion to warn him not to repeat it. No man who indulges in vice can tell what may be its consequences. It must always end in evil, and not unfrequently it results in loss of health, and in long and painful disease. This is always the case with intemperance and all gross pleasures. Sooner or later, sin will always result in misery. Do not repeat the vice. You have had dear-bought experience, and if repeated it will be worse. When a man has been restored from the effects of sin, he should learn to avoid the very appearance of evil. He should shun the place of temptation; he should not mingle again with his old companions; he should touch not, taste not, handle not. God visits with heavier judgment those who have been once restored from the ways of sin and who return again to it. The drunkard that has been reformed, and that returns to his habits of drinking, becomes more beastly; the man that professes to have experienced a change of heart, and who then indulges in sin, sinks deeper into pollution, and is seldom restored. The only way of safety in all such cases is to “sin no more;” not to be in the way of temptation; not to expose ourselves; not to touch or approach that which came near to working our ruin. The man who has been intemperate and is reformed, if he tastes the poison at all, may expect to sink deeper than ever into drunkenness and pollution.
The question for us to consider is, in what ways have we turned from our sin and is there any habitual sin in our life which we continue to struggle with? Are we seeking to avoid lawlessness and iniquity and pursue after righteousness or have we tried to “justify” our own sins? If so, we can read this Scripture and hear Jesus speaking to us in the same manner; “Sin no more.”