Chick Tracts are leading millions of people to think they can't be saved unless they're willing to stop shacking up, stop getting drunk, stop going to strip joints, et cetera.
I'm half surprised he didn't list child molestation there. Who was that guy that said, "If your hand causes you to sin, cut it off, and if your eye causes you to sin, pluck it out"? But what the hell would he know about it, right? If Dave were to follow that advice, he would be a eunuch.
As for Jack Chick, the idea that he believes in salvation through works is laughable. The one that jumps to mind is the famous missionary who meets an ex-con on an airplane. When the ex-con asks the missionary about how many thousands he has converted to Christianity on his missions, the missionary explains that he just builds schools, digs wells, organizes food drive, etc, and doesn't force them to convert. The ex-con then calls him out and explains how he's not a real christian since he didn't focus entirely on forcing people to convert, and the missionary realizes the "error of his ways" (and the fact he's going to hell) just as the plane is crashing.
Of course, Jack Chick believes in a fantasy version of Christianity where, once converted, you suddenly realize how evil drinking, gambling, adultery, etc. are and no longer have any desire to do them. That's how he can claim that anyone that actually does those thing isn't really a Christian, but simply a pretender.