Allah commanded His servant and Messenger, Muhammad , to call the People of the Two Scriptures and the unlettered idolators to his religion, way, Law and all that Allah sent him with. Allah said,

﴿ظˆظژظ‚ظڈظ„ظ’ ظ„ظ‘ظگظ„ظ‘ظژط°ظگظٹظ†ظژ ط£ظڈظˆطھظڈظˆط§ظ’ ط§ظ„ظ’ظƒظگطھظژظ€ط¨ظژ ظˆظژط§ظ„ط§ظ‘ظچظ…ظ‘ظگظٹظ‘ظگظٹظ†ظژ ط،ظژط£ظژط³ظ’ظ„ظژظ…ظ’طھظڈظ…ظ’ ظپظژط¥ظگظ†ظ’ ط£ظژط³ظ’ظ„ظژظ…ظڈظˆط§ظ’ ظپظژظ‚ظژط¯ظگ ط§ظ‡ظ’طھظژط¯ظژظˆط§ظ’ ظˆظ‘ظژط¥ظگظ† طھظژظˆظژظ„ظ‘ظژظˆظ’ط§ظ’ ظپظژط¥ظگظ†ظ‘ظژظ…ظژط§ ط¹ظژظ„ظژظٹظ’ظƒظژ ط§ظ„ظ’ط¨ظژظ„ظژظ€ط؛ظڈ﴾

(And say to those who were given the Scripture (Jews and Christians) and to those who are illiterates (Arab pagans): "Do you (also) submit yourselves'' If they do, they are rightly guided; but if they turn away, your duty is only to convey the Message.) meaning, their reckoning is with Allah and their return and final destination is to Him. It is He Who guides whom He wills and allows whom He wills to stray, and He has the perfect wisdom and the unequivocal proof for all of this. This is why Allah said,

﴿ظˆظژط§ظ„ظ„ظ‘ظژظ‡ظڈ ط¨ظژطµظگظٹط±ظŒ ط¨ظگط§ظ„ظ’ط¹ظگط¨ظژط§ط¯ظگ﴾

(And Allah sees the servants.) for He has perfect knowledge of who deserves to be guided and who does not deserve to be guided. Verily,

﴿ظ„ط§ظژ ظٹظڈط³ظ’ط£ظژظ„ظڈ ط¹ظژظ…ظ‘ظژط§ ظٹظژظپظ’ط¹ظژظ„ظڈ ظˆظژظ‡ظڈظ…ظ’ ظٹظڈط³ظ’ظ€ظژظ„ظڈظˆظ†ظژ ﴾

(He cannot be questioned for what He does, while they will be questioned.) ﴿21:23﴾ because of His perfect wisdom and mercy. This and similar Ayat are clear proofs that the Message of Muhammad is universal to all creation, as it is well established in the religion, according to the various texts of the Book and Sunnah. For instance, Allah said,

﴿ظ‚ظڈظ„ظ’ ظٹظژط£ظژظٹظ‘ظڈظ‡ظژط§ ط§ظ„ظ†ظ‘ظژط§ط³ظڈ ط¥ظگظ†ظ‘ظگظ‰ ط±ظژط³ظڈظˆظ„ظڈ ط§ظ„ظ„ظ‘ظژظ‡ظگ ط¥ظگظ„ظژظٹظ’ظƒظڈظ…ظ’ ط¬ظژظ…ظگظٹط¹ظ‹ط§﴾

(Say (O Muhammad ): "O mankind! Verily, I am sent to you all as the Messenger of Allah.'') ﴿7:158﴾, and,

﴿طھظژط¨ظژط§ط±ظژظƒظژ ط§ظ„ظ‘ظژط°ظگظ‰ ظ†ظژط²ظ‘ظژظ„ظژ ط§ظ„ظ’ظپظڈط±ظ’ظ‚ظژط§ظ†ظژ ط¹ظژظ„ظژظ‰ ط¹ظژط¨ظ’ط¯ظگظ‡ظگ ظ„ظگظٹظژظƒظڈظˆظ†ظژ ظ„ظگظ„ظ’ط¹ظژظ€ظ„ظژظ…ظگظٹظ†ظژ ظ†ظژط°ظگظٹط±ط§ظ‹ ﴾

(Blessed be He Who sent down the criterion to His servant that he may be a warner to the `Alamin (mankind and Jinn).) ﴿25:1﴾.

The Two Sahihs and other collections of Hadith recorded that the Prophet sent letters to the kings of the earth during his time and to different peoples, Arabs and non-Arabs, People of the Book and the unlettered, just as Allah had commanded him. `Abdur-Razzaq recorded that Ma`mar said, that Hammam said that Abu Hurayrah said that the Prophet said,

آ«ظˆظژط§ظ„ظ‘ظژط°ظگظٹ ظ†ظژظپظ’ط³ظگظٹ ط¨ظگظٹظژط¯ظگظ‡ظگطŒ ظ„ظژط§ ظٹظژط³ظ’ظ…ظژط¹ظڈ ط¨ظگظٹ ط£ظژط­ظژط¯ظŒ ظ…ظگظ†ظ’ ظ‡ظژط°ظگظ‡ظگ ط§ظ„ظ’ط£ظڈظ…ظ‘ظژط©ظگ: ظٹظژظ‡ظڈظˆط¯ظگظٹظ‘ظŒ ظˆظژظ„ظژط§ ظ†ظژطµظ’ط±ظژط§ظ†ظگظٹظ‘ظŒطŒ ظˆظژظ…ظژط§طھظژ ظˆظژظ„ظژظ…ظ’ ظٹظڈط¤ظ’ظ…ظگظ†ظ’ ط¨ظگط§ظ„ظ‘ظژط°ظگظٹ ط£ظڈط±ظ’ط³ظگظ„ظ’طھظڈ ط¨ظگظ‡ظگطŒ ط¥ظگظ„ظ‘ظژط§ ظƒظژط§ظ†ظژ ظ…ظگظ†ظ’ ط£ظژظ‡ظ’ظ„ظگ ط§ظ„ظ†ظ‘ظژط§ط±آ»

(By He in Whose Hand is my soul! No member of this Ummah, no Jew or Christian, hears of me but dies without believing in what I was sent with, but will be among the people of the Fire.) Muslim recorded this Hadith.

The Prophet said,

آ«ط¨ظڈط¹ظگط«ظ’طھظڈ ط¥ظگظ„ظژظ‰ ط§ظ„ظ’ط£ظژط­ظ’ظ…ظژط±ظگ ظˆظژط§ظ„ظ’ط£ظژط³ظ’ظˆظژط¯آ»

(I was sent to the red and black. ) and,

آ«ظƒظژط§ظ†ظژ ط§ظ„ظ†ظ‘ظژط¨ظگظٹظ‘ظڈ ظٹظڈط¨ظ’ط¹ظژط«ظڈ ط¥ظگظ„ظ‰ ظ‚ظژظˆظ’ظ…ظگظ‡ظگ ط®ظژط§طµظ‘ظژط©ظ‹طŒ ظˆظژط¨ظڈط¹ظگط«ظ’طھظڈ ط¥ظگظ„ظژظ‰ ط§ظ„ظ†ظ‘ظژط§ط³ظگ ط¹ظژط§ظ…ظ‘ظژط©آ»

(A Prophet used to be sent to his people, but I was sent to all mankind.)

﴿ط¥ظگظ†ظ‘ظژ ط§ظ„ظ‘ظژط°ظگظٹظ†ظژ ظٹظژظƒظ’ظپظڈط±ظڈظˆظ†ظژ ط¨ظگط¢ظٹظژظ€طھظگ ط§ظ„ظ„ظ‘ظژظ‡ظگ ظˆظژظٹظژظ‚ظ’طھظڈظ„ظڈظˆظ†ظژ ط§ظ„ظ†ظ‘ظژط¨ظگظٹظ‘ظگظٹظ†ظژ ط¨ظگط؛ظژظٹظ’ط±ظگ ط­ظژظ‚ظ‘ظچ ظˆظژظٹظژظ‚ظ’طھظڈظ„ظڈظˆظ†ظژ ط§ظ„ظ‘ظژط°ظگظٹظ†ظژ ظٹظژط£ظ’ظ…ظڈط±ظڈظˆظ†ظژ ط¨ظگط§ظ„ظ’ظ‚ظگط³ظ’ط·ظگ ظ…ظگظ†ظژ ط§ظ„ظ†ظ‘ظژط§ط³ظگ ظپظژط¨ظژط´ظ‘ظگط±ظ’ظ‡ظڈظ… ط¨ظگط¹ظژط°ظژط§ط¨ظچ ط£ظژظ„ظگظٹظ…ظچ - ط£ظڈظˆظ„ظژظ€ط¦ظگظƒظژ ط§ظ„ظ‘ظژط°ظگظٹظ†ظژ ط­ظژط¨ظگط·ظژطھظ’ ط£ظژط¹ظ’ظ…ظژظ€ظ„ظڈظ‡ظڈظ…ظ’ ظپظگظٹ ط§ظ„ط¯ظ‘ظڈظ†ظ’ظٹظژط§ ظˆظژط§ظ„ط§ظ‘ظŒط®ظگط±ظژط©ظگ ظˆظژظ…ظژط§ ظ„ظژظ‡ظڈظ… ظ…ظ‘ظگظ† ظ†ظ‘ظژظ€طµظگط±ظگظٹظ†ظژ ﴾

(21. Verily, those who disbelieve in the Ayat of Allah and kill the Prophets without right, and kill those men who order just dealings, then announce to them a painful torment.) (22. They are those whose works will be lost in this world and in the Hereafter, and they will have no helpers.)