Allah The Almighty has honored man in this worldly life and preferred him over many creatures, as confirmed by His Statement (which means): {And We have certainly honored the children of Aadam (Adam) and carried them on the land and sea and provided for them of the good things and preferred them over much of what We have created, with [definite] preference.} [Quran 17:70]
Man has been made a successor to authority, which makes him in need of the means that guarantee his survival, maintain his succession to authority and sustain his worldly affairs.
Allah The Almighty has made property a means of sustenance, as shown in His statement (which means): {And do not give the weak-minded your property, which Allah has made a means of sustenance for you.} [Quran 4:5]
Money sustains the worldly interests of people, and it is the means by which they fulfill their requirements. Man needs it as long as he is living, and once he dies, he no longer needs it. Thus, it is necessary to have a successor and a new owner of his property. If the new owner is someone who is capable of taking the property by force and overpowering others, then, it would lead to mutual hatred and disputes among people, and inheritance would be subject to power struggles and strife. If, on the other hand, the property is assigned (after one's death) to cats, dogs, and domestic animals -- which is sometimes the case in some laws -- surely, the people's benefits and interests will be lost and their needs will not be met.
For this reason, the Sharee‘ah (Islamic legislation) has assigned inheritance to the deceased person's relatives so that people would rest assured of the destiny of their property, as they are naturally eager to benefit those with whom they have a strong relationship of blood, marital relation or allegiance. If a person dies and leaves property, according to the Islamic Sharee‘ah that takes into consideration all the benefits of people, it should be distributed among his relatives with justice. This means distributing the inheritance beginning with the closest and then the next of kin to him and so on, like the children, the father and those next to them in the degree of kinship. Allah The Almighty Says (what means): {This day I have perfected for you your religion and completed My favor upon you and have approved for you Islam as religion.} [Quran 5:3]