The truest and holiest doctrines can have very bad consequences when they are not made to connect with the principles of the society ; and contrariwise, the falsest doctrines can have admirable consequences when they are made to relate to those same principles.
The religion of Confucius denies the immortality of the soul,  and the school of Zeno did not believe in it. Who would have thought that these two schools had drawn from their false principles consequences that were not just but were admirable for society ? The religion of the Taos and the Foes believes in the immortality of the soul, but from such a sacred doctrine they have drawn horrible consequences.
Almost everywhere in the world, and in all times, the misunderstood opinion of the immortality of the soul has enticed women, slaves, subjects, and friends to kill themselves other in order to go serve the object of their respect or love in the afterworld. It was so in the West Indies ; it was so among the Danes,  and it is so still today in Japan,  in Macassar,  and in several other places on the earth.
These customs emanate less directly from the doctrine of the immortality of the soul than from that of the resurrection of the body, from which the consequence has been drawn that after death the same individual would have the same needs, the same sentiments, and the same passions. From this point of view, the doctrine of the immortality of the soul has a prodigious effect on men, because the thought of a simple change of habitation is more within our minds’ compass, and more flatters our heart, than the thought of a transformation.
It is not enough for a religion to establish a doctrine, it must also direct it ; that is what the Christian religion has done admirably with respect to the doctrines of which we speak : it tells us to hope for a state we believe in, not a state that we feel or know ; everything, including the resurrection of the body, leads us to spiritual thoughts.