When you are tempted to sin, one of the counter measures that God uses to try and stop you from acting on the temptation is to show you all the negative consequences that will follow your committing that sin. The enemy, in contrast, doesn’t want you to have any awareness at all of any negative consequences that would follow if you give in to the temptation. If you have any thought whatsoever that there’s a possibility of a particular negative consequence to taking a certain action, that is one more barrier, one more hurdle that the tempter has to surpass. He would much rather you simply focus on some imagined good consequence that you become convinced will result from taking the action he is tempting you to take.
For example, there are many sins we are tempted to give into that would result in the people who know of us having a lower opinion of us. In short, if we do these things, and people find out (as so often happens), then our reputation will be ruined. But we often don’t think about such negative consequences when we are in the throes of being tempted. As we imagine the positive consequences that we believe, in the moment, will result from taking this or that action, it’s easy to gloss over or never even consider the possibility that there could be real negative consequences to the considered action.