“These are written that you may believe that Jesus is the Messiah, the Son of God, and that by believing you may have life in his name.” This is the reason John gives for writing, and was one of Jesus's reasons for walking among us. That was no less true among his early followers, and the difference between Mary and Thomas is a great example. Mary requires only hearing her own name, and Thomas is slower to believe. In both cases, Jesus knows them well enough to meet them where they are, and they respond by believing that he is the Messiah, the Son of God."