The author of the Book of John in the Bible is traditionally attributed to John the Apostle, one of the twelve disciples of Jesus.
St. Bartholomew is considered an apostle because he was chosen by Jesus to be one of the twelve original disciples who spread the teachings of Christianity after Jesus' crucifixion and resurrection. Bartholomew's apostleship is mentioned in the Bible, specifically in the Gospels of Matthew, Mark, Luke, and Acts.
John the Apostle and beloved disciple. See Revelation 1:1,4 and 9.
There is no record of this in the BibleAnswer:The death of only one apostle is recorded in Scripture: James, the brother of John, was "killed with the sword" (beheaded) by order of Herod Agrippa I (see Acts 12). Otherwise, the Bible is indeed silent on the subject.
The word twelve is mentioned in the Bible in 166 different verses. It would be impossible to list them all here. One reason it is mentioned so much is that there were twelve tribes of Israel. To see the verses, go to blueletterbible.org and do a search there.
Apostles are mentioned multiple times in the Bible, specifically in the New Testament. The term "apostle" refers to the twelve disciples chosen by Jesus, including Judas Iscariot's replacement, Matthias, and later, Paul. The specific number of times they are mentioned can vary depending on the translation of the Bible.
See the attached Related Link for a synopsis of the books of the Jewish Bible.
They were each inspired by God (see 2 Timothy 3:16-17) and usually had a scribe write down their words.
In the Bible, after the betrayal and death of Judas Iscariot, the remaining apostles decided that a new apostle needed to be chosen to replace him. This decision is described in the book of Acts in the New Testament.
It is unlikely that you will find any reliable secular sources about John. Any non-biblical stories you see are likely apocryphal.
No apostle came out and stated he was the leader. In Acts chapters 2-4 we see that Peter often took the lead when talking to government officials or Jewish religious leaders of the time. Peter also led the way for preaching to Gentiles (non-Jews) with his conversion of Cornelius in Acts chapter 10. Later on, Paul, who wasn't one of the twelve, also took on an overseer type role for the Christian congregation.
The original twelve disciples/apostles are listed in Matthew 10:2-4, "These are the names of the twelve apostles: first, Simon (who is called Peter) and his brother Andrew; James son of Zebedee, and his brother John; Philip and Bartholomew; Thomas and Matthew the tax collector; James son of Alphaeus, and Thaddaeus; Simon the Zealot and Judas Iscariot, who betrayed Him." The Bible also lists the twelve disciples/apostles in Mark 3:16-19 and Luke 6:13-16. A comparison of the three passages shows a couple of minor differences in the names. It seems that Thaddaeus was also known as "Judas, son of James" (Luke 6:16) and Lebbaeus (Matthew 10:3). Simon the Zealot was also known as Simon the Canaanite (Mark 3:18). Judas Iscariot, who betrayed Jesus, was replaced in the twelve apostles by Matthias (see Acts 1:20-26). Some Bible teachers view Matthias as an "invalid" apostle and believe that Paul was God's choice to replace Judas Iscariot as the twelfth apostle.