By which I mean an experience of understanding which is clear and conscious in the mind; therefore not primarily in words, symbols, concepts, principles, abstractions or any other indirect or representational medium.
Thus, for a Romantic Christian - the fundamental basis of his Christianity is not in the reports of other people nor any kind of history; not in tradition or words; not in any external authority or person; nor in accounts of theological or philosophical reasoning.
Instead, the basis is the experience of a positive, affirmative grasp and knowing; and it is this which needs to be applied to the 'secondary' sources of Christian knowledge that are described above. Our true faith, that sustains courage and supplies Hope, is to be derived from that which is primary.
For example, the primary truth of a passage of scripture (or history, or commandment, or rule...) may be apprehended and known by experience in this primary way - by a process which is distinct both from 'reading the words' and distinct from the words-meanings being imposed-upon the mind by the act of reading.
And when such a direct apprehension and understanding is lacking, then the scriptural passage (or whatever) should not be regarded as primary.
In sum; Romantic Christianity is rooted in active and creative thinking; and the passive and absorptive is recognized as secondary.
It also follows that the expression of Romantic Christianity can only be in the secondary forms; because the primary and intuitive, direct-knowing of the mind cannot wholly be captured or fully-communicated by any expression of it in words or any other medium. This is what makes it primary.
What is relatively 'new' about Romantic Christianity - that 'Romantic' impulse that seemed to emerge incrementally only from about the middle 1700s in Europe, and later in other places to become dominant now (apparently) everywhere - is that the engagement needs to be both conscious and chosen.
The possibility and effectiveness of a life passively-guided by true bit unconscious tradition, has dwindled; and has by now essentially disappeared among adults. Unconscious, spontaneous instinct is likewise both enfeebled and corrupted so as to become both impossible and undesirable.
We are active, conscious, choosing Christians - or we are not Christians.
Modern Man is in a new and unprecedented situation deriving from both his deficits and his capacities. Either he will choose consciously to base his fundamental (metaphysical) Christianity upon Romantic and experiential foundations; or else he will become assimilated to The World - which is (in 2021) atheistic, materialistic and (most importantly) subject to global demonic strategies.
The Romantic Christian can thus be of any denomination or none, in his practice of Christianity - according to the guidance of his experiential discernments.
But the Romantic Christian must always be in a process of rooting his faith in the personal and experiential - and this is the fact which enables him to discern and adhere to the good and Godly among the great mass of evil and Satanic influences that increasingly permeate and dominate the world of public discourse (including all the 'Christian' churches).
Note: The above was stimulated by brooding upon a marvelous and inspiring talk by Archbishop Vigano - where the Abp seems strongly to imply the need for individual discernment, yet does not explain or state it explicitly. My belief is that such matters require detailed discussion. In the past - there were internal mechanisms to deal with top-down problems; but now the evil is active, globally applied and enforced (with the coordinated aid of the secular powers: finance, government, corporations, media etc) and the corruption extends through a majority of middle and lower hierarchy and through the 'masses' and the RCC laity. Unless discernment is conscious and consciously regarded as primary, it will not suffice to combat the an onslaught of evil.