1- Jihad, defined as “to war against non-Muslims to establish the religion,” is the duty of every Muslim and Muslim head of state (Caliph). Muslim Caliphs who refuse jihad are in violation of Sharia and unfit to rule.
4- A percentage of Zakat (charity money) must go towards jihad.
The Jihad or Holy War
I seek God's help against the disbeliever.
Jihad: such definition you gave is not precize.
The Jihad is to defend the religion of God and to struggle to make the cause of the religion dignified and lofty.
It does not mean the transgression or to fight people who do not fight the Islam religion; as in the Quran
2: 190
وَقَاتِلُواْ فِي سَبِيلِ اللّهِ الَّذِينَ يُقَاتِلُونَكُمْ وَلاَ تَعْتَدُواْ إِنَّ اللّهَ لاَ يُحِبِّ الْمُعْتَدِينَ
The explanation:
(Fight in the way of God against those who fight against you, but begin not hostilities. God does not love aggressors.)
And if the enemy attacks the country of Muslims, the Jihad becomes compulsive on everyone capable of defending and fighting.
Such instruction is not invented or annovated by the religion of the Islam; in fact it was prescribed for the past nation of the Children of Israel also.
Like those who fought together with Josue son of Nun, Saul under the instructions of Prophet Samuel and Prophet and King David in their wars agaisnt the idolaters who worshipped the idols and associated them with God Almighty.
And it is true that part of the Zakat tax should be dedicated to the Jihad.
If Mohammed is truthful in his prophet-hood, then why did he use war and fighting in his mission?
[: the Jihad or Holy War]
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1- Muslim Caliphs who refuse jihad are in violation of Sharia and unfit to rule.
2- A Caliph can hold office through seizure of power meaning through force.
3- A Caliph is exempt from being charged with serious crimes such as murder, adultery, robbery, theft, drinking and in some cases of rape.
5- It is obligatory to obey the commands of the Caliph, even if he is unjust.
6- A caliph must be a Muslim, a non-slave and a male.
7- The Muslim public must remove the Caliph if he rejects Islam.
The Caliph
This term was invented by Muslims for the ruler who rules the entire Islamic countries following the death of Prophet Mohammed – salam be to him – and such term is not revealed in the Quran.
Of course his duty as the ruler of Muslims, is to fight in the cause of God and defend the country against the enemy and to help the cause of God and the religion of God against the idolatry and the association with God.
It is not revealed that the Caliph should come by force seizure of power as you said.
The caliph is governed by the law of God and he is not "exempt from being charged with serious crimes such as murder, adultery, robbery, theft, drinking and in some cases of rape." This is obviously a lie against God's religion and God's law; no one is exempt from submitting to God's law.
" It is obligatory to obey the commands of the Caliph" on condition he does not contradict the commands of God. If he contradicts the command of God, then no obedience is due to him.
6- A caliph must be a Muslim, a non-slave and a male.
True.
7- The Muslim public must remove the Caliph if he rejects Islam.
True.
Moreover, it is not necessary the ruler is called caliph or another title; the important thing is that he should observe God's law revealed in the Quran.