Jesus did not have siblings

Jesus did not have sibling brothers. The terms "brothers" and "brethren"  is used very loosely in the bible. It was used to refer to cousins and other relatives, as well as associates. This notion that Jesus did not have brothers is not a "Catholic invention". It was always understood thusly. See below.
The word "brother" is used loosely throughout the bible. In fact, it refers to many sorts of relationships including cousin, grandson, nephew and associate. Further, the word "brother" is switched with other terms to show various relationships that are not sibling relationships. John even uses the word "brothers" in a reference to the Apostles. Below are several examples.
GEN 11:31 And Terah took his son Abram and his grandson Lot, the son of Haran, and his daughter-in-law Sarai, his son Abram's wife, and they went out with them from Ur of the Chaldeans to go to the land of Canaan; and they came to Haran and dwelt there. relationship is grandson These are all the SAME relationship.
GEN 12:5 Then Abram took Sarai his wife and Lot his brother's son, and all their possessions that they had gathered, and the people whom they had acquired in Haran, and they departed to go to the land of Canaan. So they came to the land of Canaan. relationship is nephew
GEN 14:12 They also took Lot, Abram's brother's son who dwelt in Sodom, and his goods, and departed. relationship is nephew
GEN 14:14 Now when Abram heard that his brother was taken captive, he armed his three hundred and eighteen trained servants who were born in his own house, and went in pursuit as far as Dan. relationship is brother
GEN 14:16 So he brought back all the goods, and also brought back his brother Lot and his goods, as well as the women and the people. relationship is brother
MT 5:22 "But I say to you that whoever is angry with his brother without a cause shall be in danger of the judgment. And whoever says to his brother, 'Raca!' shall be in danger of the council. But whoever says, 'You fool!' shall be in danger of hell fire. relationship is associate, non-specific
MT 5:23 "Therefore if you bring your gift to the altar, and there remember that your brother has something against you, relationship is associate, non-specific
MT 5:24 "leave your gift there before the altar, and go your way. First be reconciled to your brother, and then come and offer your gift. relationship is associate, non-specific
MT 12:46 While He was still talking to the multitudes, behold, His mother and brothers stood outside, seeking to speak with Him. relationship is associate, non-specific
MK 6:3 "Is this not the carpenter, the Son of Mary, and brother of James, Joses, Judas, and Simon? And are not His sisters here with us?" And they were offended at Him. relationship is associate, non-specific
LK 14:12 Then He also said to him who invited Him, "When you give a dinner or a supper, do not ask your friends, your brothers, your relatives, nor rich neighbors, lest they also invite you back, and you be repaid. relationship is associate, non-specific
Note: brothers is not a subset of relatives, here.
JN 7:3 His brothers therefore said to Him, "Depart from here and go into Judea, that Your disciples also may see the works that You are doing. relationship is associate, non-specific
"brothers"  are the Apostles.
ACTS 9:17 And Ananias went his way and entered the house; and laying his hands on him he said, "Brother Saul, the Lord Jesus, who appeared to you on the road as you came, has sent me that you may receive your sight and be filled with the Holy Spirit." relationship is associate, non-specific
Saul and Ananias were not confused as siblings.
ROM 14:13 Therefore let us not judge one another anymore, but rather resolve this, not to put a stumbling block or a cause to fall in our brother's way. relationship is associate, non-specific
1COR 16:12 Now concerning our brother Apollos, I strongly urged him to come to you with the brethren, but he was quite unwilling to come at this time; however, he will come when he has a convenient time. relationship is associate, non-specific
Paul is not related to Apollos.
"the brethren" is non-specific
Jude 1:1 Jude, a bondservant of Jesus Christ, and brother of James, To those who are called, sanctified by God the Father, and preserved in Jesus Christ: Jude did not say Jesus Christ is his brother, but does say that James is his brother - in the same sentence.
LK 2:41 His parents went to Jerusalem every year at the Feast of the Passover.
2:42 And when He was twelve years old, they went up to Jerusalem according to the custom of the feast.
2:43 When they had finished the days, as they returned, the Boy Jesus lingered behind in Jerusalem. And Joseph and His mother did not know it;
2:44 but supposing Him to have been in the company, they went a day's journey, and sought Him among their relatives and acquaintances.
2:45 So when they did not find Him, they returned to Jerusalem, seeking Him.
2:46 Now so it was that after three days they found Him in the temple, sitting in the midst of the teachers, both listening to them and asking them questions.
2:47 And all who heard Him were astonished at His understanding and answers.
2:48 So when they saw Him, they were amazed; and His mother said to Him, "Son, why have You done this to us? Look, Your father and I have sought You anxiously."
2:49 And He said to them, "Why did you seek Me? Did you not know that I must be about My Father's business?"
2:50 But they did not understand the statement which He spoke to them.
2:51 Then He went down with them and came to Nazareth, and was subject to them, but His mother kept all these things in her heart.
2:52 And Jesus increased in wisdom and stature, and in favor with God and men.
 

At this time, Jesus is twelve years old. There is no mention of any other children on the trip to Jerusalem.  Therefore, the bible demonstrates that there were no other siblings of Jesus. If there had been, why were they not mentioned? What would have been the purpose? Also, if there had been siblings in the first twelve years of our Lord's life, why would there be no mention of them, unless they didn't exist?  Luke specifically states that this gospel is carefully researched, and that he has a "perfect understanding" of the events.

LK 1:1 Inasmuch as many have taken in hand to set in order a narrative of those things which have been fulfilled among us,
1:2 just as those who from the beginning were eyewitnesses and ministers of the word delivered them to us,
1:3 it seemed good to me also, having had perfect understanding of all things from the very first
, to write to you an orderly account, most excellent Theophilus,
1:4 that you may know the certainty of those things in which you were instructed.

The gospel does say that Joseph and Mary "sought Him among their relatives and acquaintances." It does not say that there were other children. When Joseph and Mary found Jesus, there is no mention of any other children, because there were no other children. Jesus was the only child of Mary and Joseph.

ACTS 1:13 And when they had entered, they went up into the upper room where they were staying: Peter, James, John, and Andrew; Philip and Thomas; Bartholomew and Matthew; James the son of Alphaeus and Simon the Zealot; and Judas the son of James.
1:14 These all continued with one accord in prayer and supplication, with the women and Mary the mother of Jesus, and with His brothers.
relationship is associate, non-specific
"brothers"  are the Apostles.
This reference is by Luke, a similar reference above is by John.

Copyright © 2000,2001,2002,2003 Steve Graessle