Jerusalem was the city of prophets, of the holy Temple, and the dynasty of King David.
For the importance of Jerusalem for Judaism, see: Jerusalem in Judaism
Saint Paul and Barnabas left Jerusalem for Antioch to deliver the letter from the Jerusalem Council, which clarified the requirements for Gentile believers. They were also appointed by the church in Jerusalem to share the decision with the believers in Antioch.
The first believers in Christianity lived in Jerusalem and in the area around the Sea of Galilee.
Jerusalem was the city where Jesus was crucified on the Friday, but rose to life again early on the Sunday. Many of the important events of Jesus' ministry also occurred there. The Holy Spirit came upon the believers at Jerusalem on the day of Pentecost.
Barnabas encouraged the believers in Jerusalem to accept Saul after his conversion by speaking about Saul's encounter with Jesus on the road to Damascus and his subsequent preaching of the gospel. Barnabas vouched for Saul's sincerity and transformation, leading the believers to trust in Saul's newfound faith.
they were shamed as non-believers, and ridiculed
Probably the Al Aksa mosque on the Temple Mount in Jerusalem.
The council was held out side of Jerusalem, it was called the council of Jerusalem
There is no important outcome of the council of Jerusalem. It was one of the less-important council's
Jerusalem itself is not important, the Masjid al Aqsa and access to it in Jerusalem is
The most important events occurred in Jerusalem since it was the central point of the Jewish nation and religion. However, most of Jesus' ministry occurred in Galilee.
Jerusalem is the Holy City in which Jesus spent most of his life. He was born in a small town outside the city, he was executed within the city on the Via Dolorosa, and he did his teachings in both Jerusalem temples and in Gentile territory.
Jerusalem has some significance for Christians as that is where Jesus was crucified but really it is just a city there is nothing holy or important about Jerusalem for Christians. There is nothing important about going there.