In Kenneth Samples’ book Seven Truths That Changed the World: Discovering Christianity’s Most Dangerous Ideas he makes the following statements that I found helpful regarding sin and its consequences in the life of a non-Christian and wanted to pass along:

God may use evil and suffering to get a nonbeliever’s attention and ultimately draw that person to himself (Zech. 13:7-9; Luke 13:1-5; John 9). If God protected people from the consequences of their sin, they would be far less likely to sense their deep estrangement from him. A life without pain and suffering would serve to reinforce the sinful illusion that people are truly independent and in control of their destiny. Without trials and difficulties, people would likely think everything is okay and fail to recognize their desperate need for God.

Christian apologist Walter R. Martin used to say that some people will not look up until they are flat on their back. Evil and suffering can shock people out of their life of diversion and indifference to spiritual things. Nothing serves to awaken a soul to its desperate plight like pain and suffering. Evil, pain, and suffering in this way may be used by God’s grace to bring a person to faith. C. S. Lewis so eloquently put it: ‘God whispers to us in our pleasures, speaks in our consciences, but shouts in our pains: it is his megaphone to rouse a deaf world.'”