In the name of Allāh,
the Beneficent, the Merciful.
Peace and Blessings of Allāh on Mohammad.
Allāh–the Glorious and the High,
Lord of the worlds
Mohammad–who brought the world
to our feet and eternity to our arms

Nonie Darwish states in her book Cruel and Usual Punishment (p. 20). “After Mohammed’s death, the struggle over his legacy and the fear of loosing Arabian culture and Islam, which preserved it, reappeared when many Muslims abandoned Islam. Muslims were heading for a catastrophe. Muslim leaders used violent and bloody reddah (meaning ‘bringing back to Islam”) warfare to reclaim the large number who had left the faith.” (p. 20).

True, many tribes in the countryside railed against authority after the Prophet’s death. But these were the newly-converted who were not yet taught Islam. Whereas in Makkah where those knowledgeable in Islam were, there was not a single case of dissent or rebel against authority. The process of teaching representatives from these newly-converted tribes and have them return and teach their people was time-consuming. Thus at the death of the Prophet they, being ignorant of Islam, returned to their tribal life.
In the words of Muhammad Ali:

“It is not historically true, however, that the whole of Arabia renounced Islam. There were many people who were true to the faith but whose connection with Madinah through the temporary ascendancy of the pretenders, was cut off. They were neither apostates nor the confederates of the rebels though, owing to the pressure of the latter, they could not openly side with the central government. There were many others whose only contention was that no zakat –(a 2-1/2 percent tax on the rich to help the poor)– should be levied on them…. (Given their tribal living) They could not appreciate the value of a central public treasury for purposes of nation building: hence their objection to the payment of zakat. Taking advantage of the general confusion, they refused to pay this tax. But Abu Bakr was particularly strict on this point. National unity, national solidarity, was his foremost concern, and refusal to pay taxes, if unchecked, was bound to dismantle the whole of the fabric. The safety of Islam as a faith was bound up with that of the Muslims as a nation. Hence the Caliph’s resolve at all costs to suppress this no-tax movement. He issued an ultimatum to all such tribes as had with-held zakat that war would be declared against them unless they duly paid. Refusal was tantamount to revolt.  There were thus three different causes that contributed to the general confusion at the Prophet’s death. Firstly, there were those who were the dupes of false prophets. Secondly, those who objected only to payment of taxes into the central treasury, and as such was confused with the rebels. Thirdly, there were those who were true to Islam but cut off from Muslims: not possessing the strength to fight the insurgents, they remained practically neutral….Tulaihah, one of the false prophets, sent his brother to rouse the Bedouin tribes to the north of Madinah” (After defeating the Bedouins). “Abu Bakr now embarked on the extermination of the insurrection, root and branch….It must be understood that the object of these campaigns was no more than the suppression of rebellion. It is legitimately open to every government to punish rebels, to execute their ring-leaders and, if necessary, to declare war on them. But over and above this, there were several other reasons that called for action. In the first place, these rebels had wantonly shed the blood of peaceful Muslim citizens here and there, causing disorder and disturbance. Again, they were out to extirpate the rule of Islam.”
(MA has dealt in detail on this topic in his The Early Caliphate. pp.20-26. Emphasis added).

Evidently, these rebels were fought not for apostasy but only for their refusal to pay zakat, which payment is a command from Allāh–(Qur’an 2:43, 110, 177, 277; 5:55; 58:13; 73:20).

In contrast, it is Christianity that commands death for apostasy and the Christian God (and as Christians say Jesus is God, Jesus) is complicit in the bloodiest episodes in Scriptural history where everything that breathes were put to the edge of the sword; and he bequeathed to the world a blazing legacy of “fire,” “sword,” hate and “division” (see Jesus and Mohammad-cures & war, Jesus-no peace and joy).

And after sucking dry everything pagan, Christianity took the sword to the “heathen” breast.  As Khwaja Kamal-ud-Din points out in his revealing book The Sources of Christianity  (pp. 30-32) :

“(whereas) Mithraism came from Persia, where it seems to have been flourishing for about six hundred years, the cult reaching Rome about 70 B.C. It spread through the Empire, and extended to Great Britain. Remains of Mithraic monuments have been discovered at York, Chester and other places. Mithra was believed to be a great Mediator between God and man. His birth took place in a cave on December 25th. He was born of a virgin. He traveled far and wide; he had twelve disciples; he died in the service of humanity. He was buried, but rose again from the tomb. His resurrection was celebrated with great rejoicing. His great festivals were the Winter Solstice and the Vernal Equinox –Christmas and Easter. He was called Saviour, and sometimes figured as a Lamb. People were initiated into his cult through baptism. Sacramental feasts were held in his remembrance. These statements may excite surprise in the mind of the reader of to-day; he may be disposed to doubt their genuineness, as while on one side he reads the story of the Jesus of the Church, in the legend of Mithra on the other Mithraism has left no traces in the world, although it was so powerful in the third century A.D. that, had it not been suppressed in Rome and Alexandria by the Christians with physical force, as has been admitted by St. Jerome, it would have left no chance for the flourishing of Christianity; and that it died only when most of its legends became incorporated in the simple faith of Jesus, and the Church lore fully saturated with Mithraic colours, so much so that Tertullian had to admit the fact, though in a way befitting his position. He says that the learned in his days considered Mithraism and Christianity identical in all but name.”  St. Jerome and other Early Fathers became puzzled at the similarity existing between the two faiths, but their ingenuity ascribed it to the machinations of the Devil to mock their faith.”

It will not be out of place if I quote certain of the observations made by these Early Fathers on the subject. They leave no room for any doubt or conjecture; they, on the other hand, conclusively prove the case. The following is from Tertullian:–

“The Devil, whose business is to prevent the truth, mimicks the exact circumstances of the Divine Sacraments in the Mysteries of Idols. He himself baptizes come, that is to say, his believers and followers; he promises forgiveness of sins from the sacred fount, and thereby initiates them into the religion of Mithra. Thus he marks the foreheads of his own soldiers, thus he celebrates the oblation of bread; he brings in the symbol of resurrection, and wins the crown with the sword. He limits his chief priest to a single marriage, he even has his virgins and ascetics.” (Our Sun-God, p.179. Italics are KK’s).

Justin Martyr says:–
“The apostles, in the commentaries written by themselves which we call Gospels, have delivered down to us how that Jesus thus commanded them: ‘He having taken bread, after that he had given thanks, said: Do this in commemoration of Me; this is My body; also having taken the cup and returned thanks, He said: This is My blood, and delivered it unto them alone; which things the evil spirit have taught to be done out of memory in the mysteries and ministrations of Mithra…..For that bread and a cup of water are placed with certain incantations in the mystic rites of one who is being initiated, you either know or can learn.” (Justin Martyr, Apol.II)

Cortez, the explorer of Mexico, also complained that the Devil had positively taught to the Mexicans the same things which God taught to the Christians.
St. Jerome admits that Mithra and Baal were the same, and called sons of the Lord. He says: “The Sun whom the heathen worship under the names of Lord Sun (Baal Samus) and Son of the Lord (Bor Belus.” (For more details see Christianity is Paganism).