This Lord's word explained bible study document will be, Parable of Brethren with Jesus Christ. In this document, Jesus is explaining who are his brethen.
All text taken from the version of the King James BibleMatthew 12:46-50
Jesus was talking with a certain group of scribes and Pharisees, when his mother and his brethren came and wanted to speak with him.
Matt.12:46-50 - While he (Jesus) talked to the people, behold, his mother and his brethren stood without, desiring to speak with him. (47) Then one said unto him, Behold, thy mother and thy brethren stand without, desiring to speak with thee. (48) Be he (Jesus) answered and said unto him that told him, Who is my mother? and who are my brethren? (49) And he (Jesus) stretched forth his hand toward his disciples, and said, Behold, my mother and my brethren! (50) - For whosoever shall do the will of my Father which is in heaven, the same is my brother, and sister, and mother.
So if you are doing the will (or work) of the Father which is in heaven, you are brethren of, or with, Jesus Christ. Also see Mark 3:33-35 and Luke 8:21 written below.
Mark 3:33-35 - And he (Jesus) answered them saying, who is my mother, or my brethren? (34) And he (Jesus) looked round about on them which sat about him, and said, Behold my mother and my brethren! (35) For whosoever shall do the will of God the same is my brother, and my sister, and my mother
Luke 8:21 - And he (Jesus) answered and said unto them, My mother and my brethren are these which hear the word of God, and do it.
As Paul said in II Cor. 5:20 ...we are ambassadors for Christ....
All those who hear and do the word of God the Father, which is in heaven, are brethren of, or with, Jesus Christ. This means keeping the commandments of God.
See any or all of the following documents:The Great Commandment(s)