What is the ruling on seeking help from the dead, knowing that I am fully aware of the fact that Allaah The Almighty alone is the Benefit-Giver and the Harm-Inflictor. I also know that neither the living nor the dead can bring about harm or benefit except with the permission of Allaah The Exalted?

All perfect praise be to Allaah, The Lord of the Worlds. I testify that there is none worthy of worship except Allaah, and that Muhammad, sallallaahu 'alyhi wa sallam, is His slave and Messenger.

It is worth noting that seeking relief from someone other than Allaah for something that can only be relieved by Allaah The Almighty is considered major Shirk (polytheism) that results in apostasy, regardless of the means through which help is sought or whether the being is alive or dead.

However, seeking the help of another living and present person for something that lies within human ability is permissible and there is nothing wrong with it, like when a person is drowning and asks another to rescue him. As for the dead, they are incapable of doing anything. This is why claiming that the living and the dead are the same is rejected by both logic and the Sharee’ah.

Moreover, your saying that neither the living nor the dead can bring benefit to anyone except with the permission of Allaah The Almighty is nothing but a malicious smokescreen, because we are speaking here about human power, not divine power that is boundless. If Allaah The Almighty, for instance, wants to remove a mountain or a tree from its place and bring it for your benefit, it would be easy for Him, but this in no way means that man may seek help from stones or trees on the pretext that they can neither bring harm nor benefit except with the permission of Allaah The Almighty. No sane person would do that.

In sum, we are not permitted to seek help from the dead or from an absent person, and there is a general prohibition on asking or supplicating to anyone other than Allaah The Almighty. The only exception here is that we may ask a living person to help with something that is proven to be within human ability, like when Allaah The Almighty Says (what means): {And the one from his faction called for help to him against the one from his enemy.} [Quran 28:15] 

Allaah Knows best.