﴿ وَإِذْ قَالَ رَبُّكَ لِلْمَلَٰٓئِكَةِ إِنِّى جَاعِلٌۭ فِى ٱلْأَرْضِ خَلِيفَةًۭ ۖ قَالُوٓا۟ أَتَجْعَلُ فِيهَا مَن يُفْسِدُ فِيهَا وَيَسْفِكُ ٱلدِّمَآءَ وَنَحْنُ نُسَبِّحُ بِحَمْدِكَ وَنُقَدِّسُ لَكَ ۖ قَالَ إِنِّىٓ أَعْلَمُ مَا لَا تَعْلَمُونَ ﴾

“AND LO! Thy Sustainer said unto the angels: "Behold, I am about to establish upon earth one who shall inherit it." They said: "Wilt Thou place on it such as will spread corruption thereon and shed blood -whereas it is we who extol Thy limitless glory, and praise Thee, and hallow Thy name?" [God] answered: "Verily, I know that which you do not know."”

The literal meaning of ‘khalifah’ or ‘caliph’ is ‘one who takes another’s place’—a successor. In the age of hereditary rule, it was generally used for a monarch who took the place of his predecessor. According to this usage, the word came to refer to one invested with power. When God created man to dwell on earth, He decreed that he might enjoy freedom of will. The angels became apprehensive of man being corrupted by this grant of power and free will and, as a consequence, spreading evil and causing bloodshed in the world. History showed that their fears were well founded. God was also fully aware of this possibility. But He had a particular reason for investing man with power and freedom on earth. If many human beings were to be corrupted by their power, there would also be a substantial number who, in spite of their power and freedom on earth, would acknowledge God’s greatness and power and their own helplessness. Such people would, of their own free will, adopt the path of submission and obedience to God. Although comparatively few in number, they would be specially prized above all others. They would be just like the food grains at harvest time, which, although greatly outweighed in bulk by chaff and straw, are the truly valued part of the crop. (Indeed if the chaff and straw are permitted to grow, it is solely so that people may have access to grain.)