Just like you reject the Jewish dietary law based on a voice only Peter heard in Acts, no?
It all still boils down to ‘we’re right because we said so’.
Good point but:
Number 1: Peter IS an authority because he was given authority from Jesus.Hence we do not question his authority cuz we’llbe questioning Jesus’ words.Inother words, we do not doubt who Peter is that’s why we do not doubt what he said.
Number 2:what Peter taught does not oppose what Jesus taught.From a second account ( see?):
“‘Are you so dull?’ he asked. ‘Don’t you see that
nothing that enters a man from the outside can make him "unclean”? For it doesn’t go into his heart but into his stomach, and then out of his body.’ He went on: ‘What comes out of a man is what makes him “unclean.” For from within, out of men’s hearts, come evil thoughts, sexual immorality, theft, murder, adultery, greed, malice, deceit, lewdness, envy, slander, arrogance and folly. All these evils come from inside and make a man “unclean.”’" Mark 7:18-23
From a theological point of view, we have Mark reporting the same idea so it’s not only Peter,hence 2 witnesses so far.
Not to forget that the passage is not about food per se, but about the relationship between Jews/Gentiles for it ends with:
You are well aware that it is against our law for a Jew to associate with a Gentile or visit him.
But God has shown me that I should not call ANY MAN IMPURE OR UNCLEAN. So when I was sent for, I came without raising any objection. May I ask why you sent for me?’… Then Peter began to speak: ‘I NOW REALIZE how true it is that God does not show favoritism but accepts men from every nation who fear him and do what is right.’" refer to Acts 10:9-23, 27-29, 34-35.
This same idea of not differentiating between Jews and Gentiles based on food or circumcision on ecc is elaborated by most of the disciples.
All in all, the person is reliable, his teachings are reliable and in harmony with what Jesus and all the other disciples wrote so from a theologicl point of view it is not questionable .
But when Muhammad teaches, you ask him,just like you ask Joseph Smith : in what authority? the answer is Allah of course but neither scriptures nor other prophets attested to his teachings when other disciples were in harmony with what Peter taught so more than 1 person.