The process of initiation is most often associated with the spiritual transformation of a person. Thus, the understanding of the symbol of the bridge as a union becomes inevitable.
Implementation of the connection between the physical and the spiritual. With the help of a bridge, the Earth itself was connected to the sky. A connection was made between human beings and Gods.
Therefore, the passage along the bridge thrown between the worlds, in all myths, is accompanied by trials and battles.
Sometimes it is presented as a heroic saga about the victory of the Spirit over the "intrigues of the dark forces", gloomy fears that dominate the human mind.
The sky and water bodies in this sense usually turned out to be almost identical to each other, which may have been due to the connection of the same ebbs and flows with the Moon (essentially celestial) phases noted by people.
Passing initiation, a person experiences a kind of death. The death of the old self for the birth of a new one. Thus, with the help of the transformation of certain habitual forms, the old is united with the new