the prophet (saas) said that the qur'an led people to the true path, and advised people to take it as their guide. some of the verses on that subject are:

say: "the purest spirit has brought it down from your lord with truth, to make those who believe firm, and as guidance and good news for the muslims." (surat an-nahl: 102)

say: "if i am misguided, it is only to my detriment. but if i am guided, it is by what my lord reveals to me. he is all-hearing, close-at-hand." (surah saba': 50)

this is why the prophet (saas) placed great importance in teaching the qur'an:

"acquire the knowledge and impart it to the people. learn the qur'an and teach it to the people; for i am a person who has to depart this world."42