Harsh Punishment For The Denial Of Truth
Denial of truth is the root cause of all those heinous crimes that you have mentioned. If someone knowingly and willingly denies the truth he can never do justice in any other matter too. Those good citizens who deny God are those who are unable to infer existence of God out of the evidence they can appreciate — it could be due to lack of data or lack of mental processing power. In any case God will not punish them as this falls under ‘mazoori’ or inherent disability beyond their control.
It’s important to understand that denial of truth leads criminal mindset ONLY IF it is done knowing and willingly and this is when it becomes a sin. If someone denies something no matter true or false because he believes that is false (even though mistakenly) he is not a denier of truth. He is in fact a seeker of truth and his bad he could not find the truth but that is no reason to punish him. In fact all of us are truth seekers and whether or not we were able to find the truth is something that we would know only on the day or judgement. No worries we will not be punished if we are sincere in our truth seeking efforts. Thats why people who we think have gone the wrong path may see us in Jannah
Yes, as Muslims, it is all we can do. But non-Muslims arguing against Islam won’t wait until Day of Judgment. They see the eternal punishment as unjust today so they want the justification today to accept that Allah is Just and worthy of worship. They won’t wait until death to be convinced that Allah is Just, they want to be convinced now. So what do we tell them?