Misinterpretation of 4:65

No! By your Lord, they are not believers until they make you judge the
disputes which arise between them, then find no resentment within themselves
towards what you have decided and accept it wholeheartedly.

4:65

The words in 4:65 are addressed to prophet Muhammad. These words have been misinterpreted to claim 3 matters:

1- That the prophet of God is a lawmaker besides God whose law must be obeyed.
2- Since the source of any laws authroised by the prophet are found in the hadith, then the words in 4:65 compel all believers to follow the hadith as a second source of law besides the Quran. Ultimately, those who do not accept and follow the hadith are in breach of the instructions in 4:65.
3- The promoters of this line of thought also claim that the words "they are not believers" mean that those who do not accept the hadith as a source of law are in fact disbelievers.

Before analysing the words in 4:65 it is necessary to be reminded of the definition given by God for a believer.
The definition is given in 2:285:

The messenger has believed in what was brought down to him from his Lord, and so did the believers. They a
ll believed in God, His Angels, His Scriptures and His Messengers: "We do not distinguish between any of His messengers", and they said, "We hear and we obey. Forgive us, our Lord. To You is the ultimate destination." 2:285

A believer is the one who believes in God, the angels, the Scriptures and the messengers of God.
Nowhere in the Quran is the belief in hadith a requirement for being a believer. In fact, the Quran prohibits the acceptance of any hadith other than the Quran which is described as the best hadith:

These are God's revelations (Quran) that We recite to you with truth, so in which hadith other than God and His revelations (Quran) do they believe? 45:6

God has brought down
the Best Hadith; a Book containing similarities and pairs. 39:23

Which hadith after it (Quran) do they believe in? 7:185

So in which hadith after it (Quran) do they believe? 77:50

Now we need to look at the words in 4:65 closely:

1- The words "until they make you judge" clearly indicate that the instructions in 4:65 applied to the time of the prophet and not today, for how can we expect a dead man to judge our personal disputes today? Let us say two men disputed among themselves with regards to some conditions or terms of a joint business arrangement, how can they go to the grave of the prophet to ask him to arbitrate between them?
The message we derive from 4:65 is that the believers who lived at the time of the prophet were instructed to place their trust in the prophet to judge among them regarding their personal disputes. The words continue to instruct the believers to accept the verdict of the prophet wholeheartedly. Their faith in his verdict is a reflection of their belief in him as the messenger of God.

2- Most importantly, to fully understand the message in 4:65, we need to know how the prophet of God judged between the poeple.
The Quran gives us the exact method by which God instructed prophet Muhammad to use to judge between his people:

We brought down to you (O Muhammad) the Book with the truth so that you may judge between the people in accordance with what God has shown you, and do not be an advocate for the betrayers. 4:105

The words in 4:105 confirm the clear instruction given to prophet Muhammad. He was commanded by God to use the Quran that was brought down to him to judge between the people.
The same command to use the Quran to judge between the people is repeated in Sura 5:

And We brought down to you the Book with truth, confirming what came before it of the Scripture and superseding it. So judge between them in accordance with what God has brought down, and do not follow their personal desires in place of what has come to you of the truth.
5:48

For the importance of this command, it is immediately repeated in the verse that follows:

And judge between them in accordance with what God has brought down.
5:49

In fact, using God's Book to judge between the people was the method God prescribed to all the prophets and not just prophet Muhammad:

The people used to be one nation, then God sent the prophets as bearers of news and as warners, and He brought the Scriptures down with them with truth to judge between the people in their differences.
2:213

The above words define the exact method prophet Muhammad used to judge among his people in their differences. He used the Book of God as his sole guidance, just like God commanded him, to judge people's disputes.

It follows that to know the Quran is to know how prophet Muhammad judged.
To claim that we need the verdict of stories written more than 200 years after the prophet died (hadith), when it is clear that prophet Muhammad used the Quran as his sole guidance is not only unjustified, but is totally misleading.