Hadith are graded in authenticity as sahih, hassan, da'if and mawdu from the most authentic to the unreliable. But the Qu'ran itself outranks the Hadith, being the uncreated words of Allah Himself.
And in Q.5:48, we have
For each of you We have appointed a divine law and a way of life. Had Allah so willed He could have made you one people; but so that He might try you by that which he has bestowed upon you [He willed otherwise]. Therefore, compete in doing good. Unto Allah ye will all return, and He will enlighten you concerning that wherein he differ
This explains itself and needs no explanation.