Thomas was one of Jesus's twelve closest followers (apostles). His name appears in all four Gospels of the New Testament.
Thomas had two names. His first name, Thomas, comes from an Aramaic word (the language Jesus spoke) that means "twin." Greek-speaking Christians often called him by another name, Didymus, which also means "twin" in Greek. The Gospel of John mentions this Greek name three times (John 11:16; 20:24; 21:2). The koine papyri, an early source document, confirms that the name Didymus was well known in the New Testament era.
Thomas in the Gospels
Thomas is mentioned in the lists of Jesus's twelve apostles in Matthew 10:3, Mark 3:18, and Luke 6:15 (compare Acts 1:13). While these books only list his name, the Gospel of John tells us more about him.
In John's Gospel, Thomas appears in several important moments:
When Jesus planned to go to Jerusalem where he faced danger, Thomas bravely said to the other disciples, "Let us also go, so that we may die with Him" (John 11:16).
When Jesus spoke about leaving his disciples, Thomas asked him to explain where he was going (14:5).
After Jesus rose from the dead, Thomas was not present when Jesus first appeared to the other disciples. Thomas said he would not believe unless he could see and touch Jesus's wounds. Eight days later, Jesus appeared again and showed Thomas his wounds. Thomas then believed and declared, "my Lord and my God" (20:24, 26–28).
Thomas was also present later when Jesus appeared to his disciples by the Sea of Galilee (21:2).
Thomas in Apocryphal Writings and Tradition
Two books from the Apocrypha (books included in some versions of the Bible but not considered Scripture by all Christian traditions) are identified with Thomas’s name:
The Gospel of Thomas from the writings found near Nag Hammadi in Egypt. It records 114 "secret sayings which the living Jesus spoke." Thomas supposedly preserved these sayings.
The Acts of Thomas with both Greek and Syriac versions. In this book, Jesus and Thomas are identified as "twins" because they share similar appearances and destinies. This book says that the apostle Thomas had secret teachings.
It also explains what happened to Thomas. Against his wishes, Thomas traveled to India under the Lord’s command. He was martyred there, killed with spears by an Indian king. Later, he was raised up, and his empty tomb was believed to have special powers. Today in St. Thomas, India, Christians claim to be the spiritual descendants of the apostle.