This is because Adam sinned and thus passed sin and death on to the human family. In addition, Satan’s earthly servants have persecuted worshippers of Jehovah, sometimes to the point of death, even as they did in the case of Jesus Christ.
مُنْذُ ٱبْتَدَأَ الشَّيْطَانُ أَعْمَالَهُ الشِّرِّيرَةَ ،‏ تُسَبِّبُ أَكَاذِيبُهُ وَتَوْجِيهَاتُهُ المَوْتَ لِلْبَشَرِ .‏