Based on the epistles of Paul and his own description of his conversion, it is possible that he was a rabbi, but probably impossible to prove. Some scholars, such as Maurice Goguel (Jesus the Nazarene), are more certain and do describe Paul as a rabbi. This appears to conflict with the description of him in Acts of the Apostles as a mere tent-maker, but it is true that rabbis were encouraged to learn a trade.
The concept of a rabbi was extremely new in Paul's time, and he probably didn't study under one. Sages of the time didn't have formal recognition or title.
There is no apostle named John Paul. There is an apostle named John and another apostle named Paul.
He called himself the Apostle to the Gentiles.
There is no apostle named John Paul. There is an apostle named John and another apostle named Paul.
Saul the Rabbi, also known as the Apostle Paul. Acts 7,8.
Paul wasn't stoned - he was beheaded.
The apostle who never married was the Apostle Paul.
Yes, although he was not a disciple of the living Jesus, he was an apostle and traditionally referred to as "the Apostle Paul" or "Saint Paul".
Yes, there is no definitive evidence in the Bible that suggests the Apostle Paul was married.
There is no clear evidence in the Bible that the apostle Paul was ever married.
OpinionI would say Apostle Paul wherever I use 'Apostle' as a title, in the same way as I would say Mr Smith, with 'Mr' capitalised. Less frequently, I would write 'apostle' uncapitalised if I did not intend it as a title, for example where 'apostle' is the subject of the sentence, and Paul is addressed. Use capitals to be on the safe side.
Luke was a companion of Paul, and not a apostle.