I believe not accepting the divinity of Christ in the trinity is the stumbling block. Same with Muslims, who misunderstand the trinity to mean three Gods.

Characterizing it as 'misunderstanding' is disingenous, we just don't believe it stands up to scrutiny. Any inquiries into the nature of the trinity result in the trinitarian doing one of two things: collapsing into obvious polytheism, or claiming their doctrine is incomprehensible and therefore inscruitable, neither of which are satisfying answers. Many Catholics in particular will in fact fall into what their church considers various heresies in trying to wrap their heads around what they claim to believe.

The latter of the two is probably reasonable, because claiming that a finite mind can not grasp an infinite one is a reasonable conclusion (even from a thermodynamic point of view :)).

“I and the Father are One” is the genesis.

Not all mysteries are scrutable in a given axiomatic framework, thankfully Gödel taught us that.

That's an oversimplification and not charitable. Trinitarians are perfectly capable of defending the doctrine without making stupid mistakes. I wouldn't call the doctrine "incomprehensible"; it's just beyond human understanding, in a way that we could contemplate it for the rest of eternity without reaching the fullness of what God has planted in that seed of knowledge.

It's easy to believe in the Trinity if you approach it as a little child, as Jesus encourages, and if we word it simply as the Fathers did. If we don't attempt to adorn it with our own analogies or explanations, it's elegant, simple, and transcendent.

> I wouldn't call the doctrine "incomprehensible"; it's just beyond human understanding, in a way that we could contemplate it for the rest of eternity without reaching the fullness of what God has planted in that seed of knowledge.

I am trying but failing to see the difference here. It sounds like what you're saying is, "I wouldn't call the doctrine incomprehensible, it's just that we (as humans) can't comprehend it"

> It's easy to believe in the Trinity if you approach it as a little child, as Jesus encourages, and if we word it simply as the Fathers did.

If you approach it as a little child, it's also very easy to believe in Santa Claus, but that doesn't make it any more true (or any more likely to be true either).

They/we do accept the divinity of Christ, we just don’t accept the Nicean creed version of the Trinity.

That version of the Trinity wasn’t/isn’t universal and other accepted Christian churches that don’t follow the Nicean creed - something shared with Jehovahs Witnesses.

Jehovah's Witnesses are not more accepted than Mormons as Christians in my experience. Or any other church in Wikipedia's non trinitarian category.[1]

[1] https://en.wikipedia.org/wiki/Category:Nontrinitarian_denomi...

The whole "we can progress to become gods" thing is a stumbling block to "normal" Christianity, too. As is the "these other books are also scripture".