Having received this impimatur from the leaders of the other apostles, Saul set out to fulfill his obligation to Jesus Christ.

Not that Saul would've stopped bringing the message given him by the Spirit, if the other apostles had objected, but he wanted their blessing, because they were "brothers" in spirit.

His message, as I said, was similar to the others, only more encompassing..included the Gentiles in the rewards of the Kingdon of Heaven.  

Now, when I speak of this kingdon, I'm not talking of "heaven" above.  It's the kingdon that will be established on earth, upon the return of Jesus Christ, the king.  At which time, the followers of the apostles would enjoy a special place in His realm.

Jesus died for all mankind..not just Israel, although Israel would be the first among equals in the Kingdom.

Antioch was apparently one of the original centers of the "Jesus" movement..far enough removed from Judea and the antagonism of their fellow Jews and the Roman influence. It provided a reasonably safe-haven to coordinate and make plans for spreading the word.

The first leader of the "movement" was James, the brother of Jesus.  No, not the step-brother..the blood brother.  

Give poor Mary a break.  After the birth of her "first-born", Jesus, she apparently enjoyed a healthy sexual relationship with her husband, Joseph.  How do I know this?  Because there were apparently a number of sons, other than Jesus and James, along with a sister or two.  

How can I prove that Jesus had siblings?  Read again, "first-born"..  That appelation is only used when others follow. 

James was killed by fellow Jews.."Law keepers".  It was believed that he was cast down from the temple wall.  So, it was a good reason for the rest to find a place, less dangerous to congregate.

It was in Antioch that Saul had occasion to upbraid Peter for being "two-faced". He was freely hobnobbing with gentiles, sharing their company and food, along with his buddy Saul.  But, when the others came from Jerusalem, he drew away from the Gentiles, observing strict  ways of the Jews, making it seem as though this was how he acted before their arrival.  Saul confronted him about this in front of Giod and sundry.

Peter acted like a kid who was caught with his hand in the cookie jar..bobnPaul