Question: what is the most important surah in quran?
Answer: According to a Hadith -a piece of speech or writing narrated from Prophet Muhammad or one of his rightful successors- which I heard and is not necessarily authentic but content-wise can be helpful, chapter 2 Surah al-Baqara is the most important Surah, because it contains "the verse of the throne" or Ayat al-Kursi.