You asked for my take on it and I gave it to you.
Did the Nazarenes get people to give them their life savings by telling them that Christ would be returning soon? Yes or no?
Did Christ actually come (or come back) when they claimed he would? Yes or no?
Perhaps this was a mistake on their part based on genuine belief or perhaps it was a scam. How can we know for sure?
Most important is the fact is that Christ did not come (or come back) when the Nazarenes and Paul insisted he would. Does this have negative implications with regard to the veracity of the Gospels? I think it does. You undoubtedly disagree.
Matthew 16:28: Verily I say unto you, There be some standing here, which shall not taste of death, till they see the Son of man coming in his kingdom.
Go back and look at 1 Kings before Israel rejected God as King and chose a human king instead. The kind of Kingdom that God had was a spiritual kingdom, where the only earthly government structures were the Judges and councils.
This is the kind of Kingdom that Jesus began, so yes those people did see Jesus coming in his kingdom. Now there will indeed be a physical government as well, but that won't be until the 1000 year reign of Christ spoken of in Revelations as well as Exekiel 39.