Although Matthew and Luke are the only two books of the New Testament that provide considerable information on Joseph, a word should be said about the remaining two Gospels.
Mark, the earliest Gospel written, simply does not treat the human origins of Jesus, and consequently makes no mention whatsoever of Joseph. Two facts should be noted, however: Jesus' coming from Nazareth and his profession of carpenter. On five occasions, ranging from Jesus' baptism at the beginning of the Gospel to his resurrection at the end, Nazareth is mentioned as part of the identification of Jesus (Mk 1:9,24; 10:47; 14:67; 16:6). Mark is also the only Gospel to give Jesus the title of "carpenter" (Mk 6:3). Reflection on these two facts could lead one to suppose that Jesus' trade would be learned from his father, as was the custom, and that the town from which he came would be the one where he was raised by his father. Though Mark never proceeds to this, Matthew notes that Joseph is the carpenter, and all three of the other Gospels associate Joseph with Nazareth. Without mentioning Joseph, Mark's Gospel gives these two hints which are elements of Joseph's identity in the other Gospels.
John's Gospel, which mentions Joseph by name twice, does not deal directly with the conception and birth of Jesus, but rather approaches his human origin in the context of eternal pre-existence:
In the beginning was the Word, and the Word was with God, and the Word was God.. The true light that enlightens everyone was coming into the world.. And the Word became flesh and dwelt among us (Jn 1:1,9,14).
As Jesus begins his mission by gathering his disciples, Philip acclaims his as the one "of whom Moses in the law and also the prophets wrote, Jesus of Nazareth, the son of Joseph" (Jn 1:45). The reply "Can anything good come out of Nazareth?" (Jn 1:46) indicates the difficulty involved in reconciling such a human background with divine election. John more than the other evangelists emphasizes that Jesus' town and his human parents were serious barriers to his being accepted as coming from the Father. "Is not this Jesus, the son of Joseph, whose father and mother we know? How does he now say, 'I have come down from heaven'?" (Jn 6:42). "We know where this man comes from; and when the Christ appears, no one will know where he comes from" (Jn 7:27). "Is the Christ to come from Galilee?" (Jn 7:41). "Search and you will see that no prophet is to rise from Galilee" (Jn 7:52). No prophecy had ever connected the Messiah with Galilee, much less with Nazareth. Such are the objections brought as reasons for rejecting Jesus.
The response to such objections is not to refute them, but to integrate them into the mystery of the light coming into the world to dispel darkness. Philip simply tells Nathanael to "come and see" (Jn 1:46) what great good can come from Nazareth. Being the son of Joseph is part of the identity of the awaited one. John bypasses the issue of Jesus being Son of God from the time of virginal conception, and consequently he also ignores the issue of whether or not Joseph was Jesus' "real" father. His interest is to show that he who was raised as son of Joseph at Nazareth was the one and same Son of God before the world existed (Jn 17:5,24). Jesus' replies to the objections do not deny that he is son of Joseph from Nazareth, but call for a recognition that as such he is much more: he is the living bread of eternal life sent by the Father (Jn 6:43-51; 7:28-29).
Mark lets his readers know that Jesus is a carpenter from Nazareth. John provides the central datum that Joseph of Nazareth in Galilee enjoyed no esteem among the religious leaders of Judea, and yet he was chosen to be father on earth to the eternally pre-existent Son of God. Obscure Joseph is not an obstacle as thought, but rather an instrument for the light of the world and bread of life to be presented to us.