伊斯兰国即哈里发国。它是全世界所有穆斯林的最高领导机构。因此，如果某个穆斯林国家已经给予某位哈里发合法的效忠（拜亚），并且哈里发制已经建立，那么全世界的穆斯林就不得再另立一个哈里发。这是依据先知ﷺ的圣训，他说：

he Islamic State is the Khilafah. It is the supreme leadership over all the Muslims worldwide, so if a Khalifah was given a legitimate bayah in any Muslim country, and Khilafah was established, then it is forbidden upon Muslims worldwide to establish another Khilafah. This is due to the saying of the Messenger (PBUH): .

“如果向两位哈里发效忠宣誓，那就杀掉后一位。”（穆斯林，《萨希哈》，第1853条）

“If bayah was taken to two Khalifahs, then kill the latter of them.” [Muslim, Sahih, #1853].

哈里发制度的建立，是为了依照伊斯兰所带来的概念和它所制定的律例来实施伊斯兰教法；同时也是为了向全世界传达伊斯兰的讯息。讯息的传达方式是向人们介绍伊斯兰，号召他们信奉伊斯兰，并为了安拉之道而进行圣战。哈里发亦称为伊玛目（Imamah）或信士的长官（Imaratul-Mu‘mineen）。它是一个世俗的职位，而不是与后世相关的职位。哈里发的存在是为了在人们中间实施伊斯兰，并在他们中间传播伊斯兰。它与先知的地位显然不同。

Khilafah is established for implementing the rules of the Islamic Sharia using the concepts that Islam has brought and the rules that it has legislated; and also to convey the Islamic Message to the world. The message is conveyed by introducing Islam to the people and calling on them to embrace it and performing Jihad in the way of Allah. Khilafah is also known as Imamah or Imaratul-Mu‘mineen (leadership of the believers). It is a temporal post and not a post related to the hereafter. The Khilafah exists to implement Islam on people and to spread it among them. It is definitely different to the Prophethood. .