First, if the person is particularly disturbed about the prevalence of evil in the world, it is likely that evil has touched him or his loved ones personally.
لِذلِكَ فِي ٱلْبِدَايَةِ ،‏ مِنَ ٱلْحِكْمَةِ أَنْ نُظْهِرَ لَهُ بِصِدْقٍ ٱلتَّقَمُّصَ ٱلْعَاطِفِيَّ .‏