Sunnis and Shias, the two main branches of Islam, share several core beliefs. One fundamental belief that is common to both groups is:
The belief in the Oneness of God (Tawhid) - Both Sunnis and Shias believe in the concept of Tawhid, which is the belief in the absolute oneness and uniqueness of God (Allah).
Additionally, both sects share beliefs in the importance of the Quran as the holy book, the prophethood of Muhammad, the Five Pillars of Islam (though there are some variations in practice), and the Day of Judgment.
If you have a specific list or context in mind regarding beliefs, please provide it for a more targeted answer!