Allah Most High says:

{Muhammad is the Messenger of Allah, and those who are with him are firm against the disbelievers and compassionate toward one another. You see them bowing and prostrating, seeking bounty from Allah and His good pleasure. Their mark is upon their faces from the trace of prostration. That is their description in the Torah. Their description in the Gospel is like a crop that puts forth its shoots, strengthens them, grows thick, and stands firmly upon its stems, delighting the sowers, so that through them He may enrage the disbelievers. Allah has promised those among them who believe and perform righteous deeds forgiveness and a tremendous reward.}

[Sūrat al-Fath: 29]

(1)

Allah Most High also says:

{Allah has promised those among you who believe and perform righteous deeds that He will surely grant them succession in the land, just as He granted succession to those before them; that He will surely establish for them the religion He has approved for them; and that He will surely replace their fear with security. They worship Me without associating anything with Me. Whoever disbelieves after that—it is they who are defiantly disobedient.}

[Sūrat al-Nūr: 55]

Thus, Allah promised those who believe [and perform righteous deeds] (2) succession, just as He promised them forgiveness and a tremendous reward in the former verse. Allah never fails in His promise. This demonstrates that those whom He granted succession, just as He granted succession to those before them, and for whom He established the religion of Islam—the religion He approved for them—as Allah Most High says:

{And I have approved Islam as your religion}