To restrain Jesus' activity, thinking that He had over-extended Himself, and that He couldn' t deal with the pressure. Jesus' brothers are mentioned. They were born after Jesus' birth. His brothers, at first, were not believers and were estranged because of Jesus' zeal. Later on they became believers, even writing the books of the Bible that bear their names, James and Jude.
Spiritual ties are stronger.
There may be friction between your earthly family and your spiritual family, especially if your earthly family are not believers. This was true in the passage under consideration, that Jesus' brothers were not believers. Look to the Lord for grace to live through trying times, and keep praying for the salvation of your family. Be a positive, steady witness to the grace and salvation of the Lord Jesus Christ. God has ordained the family, and it is important.