The Trinity is a fundamental doctrine (error) of orthodoxy, and those of us who don’t share this doctrine are accused of all manner of heresy.
First of all we do believe in the divinity of Christ despite what our accusers say, that is that following his sacrifice on the cross and subsequent resurrection he was highly exalted to the divine nature the same nature or divinity as that possessed by the Father.
We also believe that our Lord was prior to his becoming flesh (Theos) a god or mighty one, and that even now he is Theos a god or mighty one, but we don’t believe nor have we ever believed that he is Ho Theos, THE mighty one, the Almighty Himself.
As for your statement that 1 John 4:3 is a litmus test, that indeed it is, however it does not translate as you suggest, but to the contrary it wholly contradicts the doctrine of the Trinity altogether.
By this test all so-called “Orthodox” doctrines are condemned because none believe that our Lord literally came in the flesh, preferring to believe that the Lord whom they claim is also the Father Jehovah God, that he merely pretended to die on the cross, as he is immortal and cannot die, this would have been a ruse or deception, a lie which is impossible for God.
Therefore, “Whoever transgresses (commits willful sin) and does not abide in the doctrine of Christ (most importantly the doctrine of the ransom) does not have God. He who abides in the doctrine of Christ has both the Father and the Son (two distinct individuals). If anyone comes to you and does not bring this doctrine (does not believe that Christ was made flesh for the purpose of becoming our ransom), do not receive him into your house nor greet him.” 3 John 9, 10
It is not our wish to get into a debate with any on the Trinity here as that is not specifically what this thread is about, there are plenty of threads arguing the Trinity on this forum for that particular discussion, one which we have found to be a waste of consecrated time, seeing as most are adamantly convinced of their position and are not likely to concede they may be in error.
Jesus is not the Father, he is the only begotten Son and no one comes to the Father but through the Son, so the Holy Spirit is that that we pick up as to who Christ Jesus truly is Emmanuel 'God with us' because that who Jesus is, he came down for us.
Now no one can know the Father, but through his begotten Son who with the Holy Spirit can be enlightened to see God the Father. so anyone who claims to not to acknowledge Jesus as our God is of Satan and that's clear.
So no one can fathom God the Father but through his only begotten Son.
Jesus showed us and he is the Light for Man, he is our Sheppard and we are his Sheep, so if we turn from him the wolfs will devour us, many in Christianity now do not look to Jesus at all truly, they are on about social gospel, they are only on about there church and just mans works and stupid man mad doctrines, such do not follow Christ Jesus at all, they are like the Golden Calf mob who had the Government as there God, who will provide for them and lead them, just like the People who played there games so as to kill Jesus Christ. because they did not want him, they have not the Holy Spirit in them and just as Saul did not have the Holy Spirit until he became Paul.
All people are blind to Christ Jesus who are not Born Again, water Baptised do not know who Jesus Christ truly is, because they have not the Holy Spirit, they only have some faith and that can be as is said about the seeds and sower, so such can loose there faith because they never truly was total faith that can move mountains, so they look outside of Jesus for there faith and embrace man made filth like Socialism and such pathetic rubbish that has noting to do with Jesus Christ at all.
Socialism is just like the works of the Golden Calf mob, where the government is above you, not God, the works of Socialism is not under Grace at all, they may claim to bringing in the Kingdom but they do not want God in it and that's clear to see. free for all Capitalism is Satanic as well.
But Satan the one who leads astray the whole world works to bastardise Capitalism giving such power to evil people who only use it to serve madness and the Socialist works to play silly buggers as well, so that your eyes are always averted to the reality's and then we get disunity and that's how Satan works to dived and conquer, turning Nations upside down.
Two of the biggest workers of Satan are the extreme Right wing and the extreme left wing, fact is they are both mates that work only to mislead the majority with all their game plays, billions of your tax money goes into fooling you with there game plays.
Without the Truth of the Trinity you only have Satan at your door and anyone who slanders that Trinity is of Satan or a fool.
The 3 are all one in the same but of different identity's.
I have seen some make claims of what the trinity is like JW it was pathetic and totally stupid nonsense that was like a 4yo may believe, I was like you have to be joking that's straight out slander, Devil you ! no Christian Church claims such rubbish as that at all.