Contrary to other legal systems, in the Islamic legal system, when you talk about right to life it does not only refer to the physical life.
Although compared to other creatures, great significance is attached to mankind's physical or material life and its rank is higher than that of animals and plants, man's spiritual life deserves more significance. It enjoys a much higher rank. The Holy Quran refers to it as 'Hayate Tayyebeh':
مَنْ عَمِلَ صَالِحًا مِنْ ذَكَرٍ أَوْ أُنْثَىٰ وَهُوَ مُؤْمِنٌ فَلَنُحْيِيَنَّهُ حَيَاةً طَيِّبَةً ۖ وَلَنَجْزِيَنَّهُمْ أَجْرَهُمْ بِأَحْسَنِ مَا كَانُوا يَعْمَلُونَ
Whoever does righteousness, whether male or female, while he is a believer - We will surely cause him to live a good life, and We will surely give them their reward [in the Hereafter] according to the best of what they used to do.(Quran, 16 :97)
A good life is what makes human discrete from other creatures. It is a sign of man's merit compared to the other creatures, because access to the spiritual life is only possible by mankind. Other creatures do not benefit from it. The importance of man's material life and the reason for equalizing it to the life of all mankind is that God determines right to life for each individual so that while enjoying this divine gift and benefiting from talents bestowed upon him, man can continue the evolution and development toward spiritual perfection aimed at achieving the spiritual life.
Thus, killing a man and depriving him of his life means violation of 'reality of mankind' which is a divine gift and is considered the grounds for transcendental perfection of mankind. In the eyes of Islamic school of thought a man not only enjoys the right to material life, he also has the right to live in a cleansed society free of corruptions and free of uncontrolled moral behavior, no intrigue, so that he can improve himself spiritually. Obviously safeguarding his spiritual life is as important as protection of his material life which has been stressed by Islam.1
- 1. Declaration of Human Rights in Islamic Law, Article 17.