8. Blood ties do not necessarily create bonds between Spirits. The body comes from the body. But the Spirit does not proceed from the Spirit, since the Spirit already existed before the formation of the body. The parents do not create the Spirit of the child; they do nothing more than supply the material wrapping, although it is their duty to help the intellectual and moral development of their child, in order to further its progress.
Those incarnated in the same family, especially as close relations, are as often as not congenial Spirits linked by past relationships, which express themselves during their earthly lives by their reciprocated affections. But it can also happen that these people are complete strangers to each other, or they may be distant from each other due to past aversions which while on Earth are translated into mutual antagonisms which serve as probations. The real family ties are not those of blood then, but those of mutual sympathy and the communion of ideas which hold spirits together, before, during and after their incarnations. From this it follows that two people born of different parents may be more like brothers or sisters than if they were of the same blood. They can attract each other, search for each other and so feel happy together; whereas two blood brothers may be repelled by each other, as is frequently seen. This moral problem is one that only Spiritism can resolve through the explanation of the plurality of existences. (See chapter 4, item 13.)
So, there are two kinds of families: Families through spiritual ties and families through bodily ties. In the first case these ties are durable and strengthen with purification, perpetuating in the spiritual worlds by means of the various migrations of the soul. In the second case, the ties are as fragile as the physical body itself, extinguishing with them and in many instances dissolving morally even in the actual existence. This was what Jesus was trying to make comprehensible when He said to His disciples: "Here is my mother and my brothers by spiritual ties, because all those who do the bidding of My Father, who is in Heaven, are my brothers, my sisters and my mother."
The hostility felt by His blood brothers is clearly expressed in this narrative from Saint Mark, when it says that they had intentions of laying their hands on Jesus, under the pretext that He had lost His Spirit, or gone out of His mind. On being informed of their arrival and knowing full well the sentiments they harboured against Him it was only natural for Jesus, speaking in spiritual terms, to refer to His disciples as His brothers and sisters. Although His mother was accompanying His brothers, Jesus generalised the teachings which in no way implies He intended to declare that His mother, according to the physical body, was nothing to Him in spirit nor that she deserved only indifference, as He proved on many occasions.