Another thought on this first line of the creed that may be helpful here is the little preposition, 'in'.
We believe IN God.
Speaking as one coming from an Evangelical background (where one's personal encounter with God is sressed), it is important to my understanding to realise that God will be MORE to a believer than merely an objective factuality.
One may believe THAT such a Creator exists - but do I believe IN Him? A philosopher may come to the conclusion that an Absolute must exist, but could that philosopher honestly state the creed?
I see something essentially existential in the opening statement of the creed. Am I on track?