People often look at the four Gospels and wonder why there are slight differences between them. They all share the same essential message, that Jesus was the Son of God in the flesh who lived and died and rose from the dead. Yet each Gospel has it's own particular lens of looking at Jesus: to Matthew Jesus is the Messiah, to Mark he is the Lord, to Luke he is the Divine Healer, and for John the Son of God. Vatican II's document on Divine Revelation, Dei Verbum, tells us that scripture is "the words of God, expressed in the words of men" (DV 13).
By way of analogy, this video does a great job of showing how different photographers, trying to emphasize a particular idea, produced different views of the same man. Again, like the Gospels, the essence of the man photographed is the same, the lighting, angle, and setting give different perspectives.