Christadelphian beliefs impact on their view of the Apostle’s Creed, though that Creed is not something mentioned much (if at all) in their literature.
Their literature does make it clear how antagonistic they are towards all the fundamental doctrines of what they call ‘Christendom’, so that we can conclude they would never subscribe to that Creed. To substantiate this, let me quote from ‘Who Are The Christadelphians?’ pp 3, 6, 8.
“Convinced that this is the only Scriptural constitution of the ‘one
body’, of which Jesus Christ is alone the head, and Who has no
personal representative on earth, we repudiate the popular churches,
and all their adjuncts, as no part thereof, and affirm that there is
no salvation within the pale of any of them. For we hold that the
religious opinions and sacramentalism of all orders and classes of men
in ‘Christendom’ so-called are nothing more than that ‘strong
delusion’ sent of God upon all mankind that they should believe a lie,
that they might all be condemned. We object to the fundamental
doctrines of Christendom; the religion of the churches and chapels is
a negation of Bible teaching on almost all points. We hold it to be
‘the abomination of the earth’ with all dissenting names and
denominations, aggregately styled ‘names of blasphemy’, of which the
European body politic, symbolised by the eight-headed,
scarlet-coloured beast is said to be ‘full’.”
On that basis, they could not possibly assent to the Apostles’ Creed, for that would align them with an ancient tradition which they despise and which they claim is cursed of God. Yet, technically, they could agree with it, if their interpretation of the doctrines involved was understood as the meaning. For example, the Creed expresses belief in “the resurrection of the flesh”. Christadelphians do believe that when Christ returns, they and the Jews will be resurrected with physical bodies on to the earth (but not to heaven). That, however, falls far short of orthodox Christian teaching about all the dead being resurrected.
You mentioned their repudiation of the Trinity doctrine, and here is what Roberts said about it in ‘Christianity Astray’ p 108
“A contradiction, a stultification, an impossibility.” “There were not
two or three eternal persons before ‘the man Christ Jesus’, but ONE –
God the Father, whose relation to the Son was afterwards exemplified
in the event related by Luke (i. 35)… Jesus Christ, the Son of God, is
not ‘the second person’ of an eternal Trinity of Gods [sic], but the
manifestation of the ONE ETERNAL CREATOR.”
Regarding Jesus Christ, Walker writes in ‘Truth About The Trinity’ p 13,
“The Father was manifest in the flesh, not a pre-existent co-eternal
Son, which is impossible.”
And in ‘Constitution of the Christadelphian Ecclesia’ p 13 we read,
“That ‘Christ’s nature was immaculate’ is among the doctrines to be
This means that although they could agree with the Creed on many points, their rejection of Christ’s pre-mortal existence, denial that he had a sinless nature when on earth etc. means that their idea of who Christ is differs vastly from the Christ of the Creed even though the Creed does not spell such details out.
The Apostles’ Creed is, on the surface, a very simple declaration of basic Christian faith, yet there are so many denominations (like the Christadelphians) who will not be aligned with it, the question, ‘Why not?’ can only be answered with, ‘Because the early Church circa A.D. 400 came up with it, and such new groups so differ from mainstream Church doctrine, they cannot be identified with that which they claim was already corrupted by then.”