They don't save anyone, Jesus does. Man can say nice things that changes a man's mind, but to be saved Jesus has to change the heart.
There was a preacher 150 years or so ago who did things like most churches do now. He said "The success of any measure designed to promote a revival of religion, demonstrates its wisdom". His preaching seemed, at the time, to produce fantastic results, but a co-worker later wrote "What was the state after we left? . . . (it was a) sad, frigid, carnal, contentious state into which the churches had fallen . . . very soon after our first departure from among them".
Towards the end of his life this preacher wrote "I was often instrumental in bringing Christians under great conviction, and into a state of temporary repentance and faith . . . [But] falling short of urging them up to a point, where they would become so acquainted with Christ as to abide in Him, they would of course soon relapse into their former state".
Paul writing to Timothy says that "All Scripture is inspired by God and beneficial for teaching, for rebuke, for correction, for training in righteousness". Acts, which is Scripture, tells us how the Apostles preached to the unsaved. This is what the Apostles did; this is what Paul did; this is what Scripture tells us; so on what grounds can we say that it should be done another way?