Shi`ah are generally considered to be Muslims. 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. We should not give them this chance.

Here, we’d like to stress the fact that at a time when the enemy of Islam encroaches the Muslim Ummah, elements of enhancing unity should dominate and creedal disputes between different Muslim groups and sects are to be avoided. We do admit that there are shortcomings in some sects, but do you think that the time is ripe to discuss such shortcomings now?
hence, Muslims should beware of all routes and channels that may lead to divisions, differences and conflicts among them. They should abide by the Qur’an and Sunnah, which are the assured means of salvation. Almighty Allah says: (And hold fast, all of you together, by the covenant of Allah and be not divided among yourselves; and remember with gratitude Allah’s favor on you; for ye were enemies and He joined your hearts in love, so that by His Grace, ye became brethren; and ye were on the brink of the pit of Fire, and He saved you from it. Thus doth Allah make His Signs clear to you: That ye may be guided. ) (Aal `Imraan 3: 103)
In our day and age, it is more important to stress points of agreement rather than points of disagreement and to try to bring a bridge between the Sunnah and the Shi`ah without compromising any Islamic values, because what unites Muslims is much greater than what disunites them.
With the enemies of Islam trying hard to sow the seeds of discord among us, we should try our best to render their attempts futile.
As for the difference between the Sunnah (Sunnis) and the Shi`ah, Dr. Mahmoud `Akkam, professor of Shari`ah at Syria University, states the following: “The difference between the Sunnah and Shi`ah can be clarified as follows:

1-The Sunni, in narrating the Prophetic Hadiths, follow certain methods and ways in sharp contrast to those followed by the Shi`ah, who prefer what is narrated by the household of the Prophet, peace and blessings be upon him.

2-The Sunni maintain that Abu Bakr, may Allah be pleased with him, has a greater advantage over others when it comes to assuming the post of caliphate, while the Shi`ah claim that `Ali, may Allah be pleased with him, was supposed to be the first and only caliph after the demise of the Prophet, peace and blessings be upon him.

3-The Shi`ah claim that Imamship or Imamah is part and parcel of the pillars of Islam. They mention those whom they deem deserving the honor of caliph, Imam or Muslim leader in order. However, the Sunni don’t see Imamship as part of the pillars of Islam.

For instance, Imam Al-Ghazali says: “The (essence of) religion is to believe in Allah in addition to certain pillars (mentioned by `Ulama) other than that is “Furu`, i.e. branches” (secondary matters in religion).”

4-The juristic rules approved by the Sunni are very different to those acknowledged by the Shi`ah. For example, the Sunni authorize the consensus of `Ulama Al-`Ijma` as one of the fundamental sources of legislation, while the Shi`ah maintain the contrary.

These are the main points of difference between the two.”