They have divided hearts. And, of course, many who profess to be Christians never have been born again. Second, because of the lack of power, many Christians do not have the backbone to confront sinners with a message that includes the fact that the sinner must repent to be saved. Even many Christians get mad at a preacher that says they need to repent of various sins including watching the filth on television, worldliness, lukewarmness, covetousness, gluttony, and many other sins in the lives of most Christians in this country today. Third, most evangelists or soul winners want to minimize rejection, so they try to make it as easy on the sinner as they can, thereby leaving out the need for repentance to be saved.
Many evangelists are more concerned about numbers than they are about true converts.
They think if they can at least get them to make a profession and get them to come to church, then maybe they will get saved later. If Satan can't stop you from evangelizing, this is exactly what the enemy of our souls wants evangelists and soul winners to do. The devil knows that those who make professions but are not truly converted are not likely to hear a complete Gospel message in the meetings of the saints, which is to say, they are not likely to hear of their need to repent to be saved. Telling someone he is a sinner is nothing new to him. He already knows he is a sinner and very likely will admit it.