Channeling, in the sense of letting a foreign non-physical entity occupy one's mind / body / voice in place of oneself, is a form of possession, and thus spiritually insupportable. This is also known as trance mediumship, as in entering a trance to becoming an occupied/possessed medium for another being or essence.
Any entity seeking to commandeer a human vessel for their own gain must be severely interrogated. It is likely that only entities/forces who seek undue power on the Earthly plane would seek to occupy a member of the Earthly plane as to gain direct access to perpetrate their cause without interference in relaying their message.
Genuine beings do not need to occupy a person in order to be heard and trusted.
This is different from entering a trance or semi-trance state in order to gain access to the subconscious mind or quantum field. The differentiation is in whether one retains spiritual sovereignty over themselves or abdicates it to another being who does not have genuine claim over one's vessel.
Contrast with Direct Cognition.
New Age Mainstay
Channeling-via-occupation (channeling by self-induced possession, AKA trance mediumship) is a tenant of the New Age / False Light movement and a mainstay of the power tactics of Luciferian Evil, with non-physical entities gaining people to their cause by speaking directly to them in the physical realm through a host, appearing positive on the surface but ultimately behaving in spiritually questionable ways — such as with occupying a human to gain recognition.
Most importantly, the True Living God would not seek to occupy a human to relay his guidance, for the Creator does not need to occupy the Created over which s/he has domain. Anyone claiming to be possessed by and channeling God (in any form, or known by any other name), is not channeling the True Living God but an imposter. See Direct Cognition.
People who participate in metaphysical dealings such as self-possession often do so from the ego, seeking whatever fame and attention the channeling-via-posession grants. This is a basic tenant of New Age Narcissism. Even if the person feels they are not seeking the attention, they operate from a place of ignorance as to the consequences of self-possession and spiritual abdication; for the infiltrating entity definitely is seeking that attention, and a person who grants their voice to the entity becomes complicit with any anti-conscious behavior or information the entity engages in or purports.
This behavior of being possessed and giving voice to those who may not have earned having a voice in this realm is fundamentally anti-spiritual (IE does not live up to the integrity of the Divine Spirit), yet prevalent among Luciferian False Light ideology and mainstream "spirituality."
Most of all, voluntarily making oneself possessed abdicates a person from their Spiritual Sovereignty, even abdicates access to their own body, which the infiltrating entity certainly capitalizes upon. This is why non-physical beings of genuine spiritual integrity would not participate in it even if demanded; see Direct Cognition below.
God does not endorse this. A person's body was made in Divine Image for that person and no one else. If a person needs to know something, they ought to consult God-within rather than let themselves be occupied by an entity-without just to gain information and mental reassurance.
Direct Cognition is superior to channeling or otherwise receiving information externally.