The eminent Muslim scholar Sheikh Yusuf Al-Qaradawi points out: “We have seen all over the world how all the religious groups and sects try to reconcile their differences; the Jews are trying to have common ground with the Christians, so they claim innocence to what the history records of the Jews’ responsibility in crucifying Jesus. The same happens among the Christians as they are trying to bring together all the Christian denominations around the world.
Amidst all these amiable gestures, where do we Muslims stand? Why do we kindle the fire of disagreement? What is the reason for all this argument about Shi`ah as if they are not Muslims?
Let it be known to all that the Shi`ah are Muslims who believe in the Oneness of Allah and the Prophethood of Muhammad (peace and blessings be upon him).
Yes, there is no doubt that the Shi`ah have their beliefs and dogmas which we condemn as heresy but this doesn’t make them non-Muslims.
We should try to make use of what we have in common for the benefit of all Muslims. No one can deny that all Muslims, Sunni and Shi`ah, condemn the Zionists and what they do against our brethren in Palestine. We maintain the same view concerning the persecution of Muslims in many parts of the world. This means that we have many things in common, which should be the pivot of our interaction.
all Muslims should be alert against the schemes and plots planned by the enemies of Islam. They are the ones that want us to disagree and fight each other. Now they resort to another scheme by filling our minds with hatred against one another under the name of belief. We should not give them this chance.”

Shedding more light on this thorny issue, Sheikh `Atiyyah Saqr, former head of Al-Azhar Fatwa Committee, states:

“Whenever we use the word Shi`ah, we are referring to a group of people who are the followers of Imam `Ali (may Allah be pleased with him) and they show full fidelity to Aal’ Bayt (the household of Prophet Muhammad). Such fidelity is required of all Muslims, and this is pursuant to many Qur’anic verses.
allah Almighty says, (Allah’s wish is but to remove uncleanness far from you, O Aal’ Bayt, and cleanse you with a thorough cleansing. ) (Al-Ahzaab 33: 33)
also, there are many hadiths that urge Muslims to give due regard to the household of the Prophet (peace and blessings upon him). For example: “Fear Allah concerning my household (by giving them due regard)”, said the Prophet three times. (Reported by Muslim)
however, some people have gone to extreme in showing fidelity to Imam `Ali to the extent that they deify him. Others claim that he was supposed to be the last Prophet as Gabriel mistakenly brought the revelation to Prophet Muhammad (peace and blessings be upon him).
Some of them adopt the idea that Prophethood is co-ownership between the Prophet (peace and blessings be upon him) and `Ali whom they take as deserving the caliphate directly after the demise of the Prophet (peace and blessings be upon him). This follows their claim which they consider to be an implicit authorization from the Prophet (peace and blessings be upon him) himself. Thus, to them, `Ali and his descendants have the sole right to the caliphate and not Abu Bakr, `Umar or `Uthman, and that it is a great injustice of the Ummah to deprive `Ali and his offspring of this right.