There are some people who fail to realise the gravity of their sins, and this is why they are perfectly content living their lives without God.

However, American evangelist Billy Graham says there is danger when people are "numb" to their sins, pointing out that they are still guilty of wrongdoings no matter what their conscience dictates.

"You are guilty when you sin – whether you feel guilty or not. The Bible solemnly warns, 'People are destined to die once, and after that to face judgment' (Hebrews 9:27)," Graham writes in an advice column for the Bowling Green Daily News.

Graham says feelings are not always the most reliable gauge for the truth, so people must not be misled by it.

"I may be convinced that nothing is going to happen to me if I walk down a dark alley at night—but my feelings may be wrong, and I actually may be placing myself in great danger," he states as an example. "Or I may be convinced I'm in good health and have nothing to worry about – but a deadly cancer still may be growing undetected inside me. Our feelings may mislead us – but facts never will."

Graham, one of the most influential Christian speakers of all time, also urges people not to ignore "the little voice within" that prompts people to do the right thing and rebukes them every time they do something wrong.

"Tragically, that voice (which we call our conscience) can become dulled or almost silenced if we refuse to listen to it," he says. "The Bible warns us to listen to what God is telling us, 'so that none of you may be hardened by sin's deceitfulness' (Hebrews 3:13)."