"What should I say to someone who acknowledges his sins, but says, ‘I just hope God is forgiving’?"

These people could be referred to as "awakened, but not alarmed." explain that God is forgiving—but only to those who repent of their sins. Ask him, "If you died right now, where would you go?" If he says, "Hell," ask if that concerns him. If it does concern him, ask, "What are you going to do?" Then tell him that God commands him to repent and trust the Savior. If it doesn’t concern him, speak of the value of his life, the threat of eternal damnation, and the biblical description of hell. Caution him that he doesn’t have the promise of tomorrow, and plead with him to come to his senses.