Final answer:
After being seen by the 500 brethren, the risen Jesus appeared to his apostle Thomas and other close followers, confirming his resurrection and reinforcing their faith. This led to the spread of Christianity by his followers, who recognized him as 'the Christ.'
Step-by-step explanation:
After being seen by the 500 brethren, the risen Jesus was seen by several of his closest followers. According to the New Testament, after the Resurrection, Jesus appeared to his disciples several times. One noteworthy appearance was to his apostle Thomas, as recorded in the Gospel of John (20:24-29), an event known as the Incredulity of Thomas. In this occurrence, Thomas, who initially doubted the resurrection, was offered proof by Jesus himself, who invited Thomas to touch his wounds. This resulted in Thomas's exclamation of faith, "My Lord and my God!"
The encounters with the risen Jesus reaffirmed the faith of his followers and were crucial to the spread of Christianity by the apostles. Jesus's post-resurrection appearances fostered the early Christian belief that he was "the Christ," which means "the anointed one" or savior, confirming a central element of Jewish theology that anticipated a messiah.