If by "anecdote" you mean he is reporting what someone else told him (whether they were eye-witnesses or not), then that would surely depend on how reliable their information was. A statement by an eye-witness is not worth less if a copper writes it down (and gets the eye-witness to sign it off) than if the eye-witness wrote it down him/herself (assuming the eye-witness can write).
Here are the problems. You do not know how reliable the information is because you do not know how Matthew came by it. You do not know if an eye witness told him or wrote it down or told somebody else who wrote it down. You do not know if the eye witness was an honest person or prone to lying. You do not even know if there was an eye witness or if somebody just made it all up, or some combination of the two.
Even if you did know there was an eye witness, eye witness testimony can often be unreliable, especially if the eye witness is under stress.
Would you care to elaborate on the reasoning that led them to that conclusion?
I can't. What I can do is point out that they were 1900 years nearer the event than you or I though.
That means nothing. You still don't know how they came to that conclusion.
Papias and so on.
But we don't have Papias's work and even if we did, he apparently admitted he got his information second hand, plus his description of "Matthew's gospel is blatantly not the work we have today.
Incorrect, unless you are saying that the quotes we have today were definitely the very first ones ever written down. Papias died, what 140ADish.
I'm saying the quotes we have today are the ones we have. If there are earlier ones that are lost, that's bad luck for you, but we don't have to pretend evidence existed once just because you deem it unfair.
The Didache is probably late 1st century, early 2nd century.
Does it tell us who wrote the gospels? No.
We have the first epistle of Clement from right the end of the first century.
Does it tell us who wrote the gospels? No.
We have Paul's letters, even if we only accept 7 of them.
Do any of them (including the other six) tell us who wrote the gospels? No.
We have Josephus and Tacitus telling us of a Jesus in Judea.
Telling us of a Christ, neither of them giving us their sources.
None of this requires us to have a belief in the inerrancy of the Scriptures to believe that the sources we have are sufficient to know that there was such a Jesus, that he was crucified and buried and that starting a couple of days later, individuals and groups of people were convinced that on about a dozen occasions (that we have recorded) they met, talked and sometimes ate with him.
This is disingenuous of you. You have cited a number of documents that appear to support the idea that Jesus was crucified and then you conflate the crucifixion and resurrection as if these documents all support the resurrection appearances that are only described in the three gospels.
OK with that, but the NT tells us that he was put in someone else's tomb.
But are the NT accounts true? They were all written many years after the events by persons unknown and the original source or sources are unknown.
What is needed is that the probability of it happening (on the background evidence) is higher than the probability of us having the evidence if the resurrection did not happen (as I think you and I agreed on another thread).
No, you have got that wrong. What you need is that, given the evidence, the probability that Jesus was resurrected is higher than the probability that something else happened. I can go into the reasoning in detail but there is no point because one of the things we need to assess along the way is the probability that Jesus was resurrected with or without evidence. I would argue that probability is very very small which means you need extraordinarily good evidence to counter the other possibilities like delusion or lying. You, on the other hand, claim God can increase that probability, but invoking God makes all probability calculations meaningless.
A religious cult that actively proselytises? What more motive do you want?
A decent motive.
The one I just gave you was an excellent motive. The fact that you do not like tells us more about your flawed thought processes than anything else.
Wanting to convert someone to a religious belief which highly prizes honesty and membership of which might well lead to persecution and, possibly, death does not seem to me to be a good reason for lying to people.
Christianity certainly prizes honesty amongst the ordinary members but its leaders have a chequered record in that department, to say the least. The leaders of religious movements tend to accrue sizeable wealth and power in comparison to the flock.