If there are believers in Catholicism it’s a dark place as in "no light"of the gospel . That can be seen in a couple of ways.
One way is as the scriptures informs there must be heresies as private interpretations or personal commentaries of men .It also inform us the ones that are damnable or judgeable are the one that deny the grace of Chris as a finished work, which the Catholic fathers do deny by assuming the work of Christ's faith gave a remnant of the grace needed to hear God and not the fullness thereof.There fullnes is met in a creature they call Mary the queen of heaven as if she was a source of grace.They say she visits purgatory and even Protestants are there working for an unknow time (forever)
Not all heresies as opinions of men are damnable just the ones that clearly show others have blasphemed the name of God by having the faith of Christ, as the work of Christ that works in the beliver to both will and do His good pleasure having that in respect to the Pope and the succession of sinful men they call fathers. There is no imputed rightousness taught in Catholicism . but rather men have faith in respect to sinful men whom they must seek the approval of. Making the word of God without effect
2Peter 2:1 But there were false prophets also among the people, even as there shall be false teachers among you, who privily shall bring in damnable heresies, even denying the Lord that bought them, and bring upon themselves swift destruction.
Another is how they follow after necromancy seeking after workers with familiar spirits (disembodied spirits) that they call patron saints. It is a damnable heresy making the portions of scripture that clearly show when a person leaves here under the sun there is no work they could perform .
Isa 8:19 And when they shall say unto you, Seek unto them that have "familiar spirits", and unto wizards that peep, and that mutter: should not a people seek unto their God? for the living to the dead?
Isa 8:20 To the law and to the testimony: if they speak not according to this word, it is because there is no light in them.
Strongs lexicon...01875 darash {daw-rash'}
a primitive root; TWOT - 455; v
AV - seek 84, enquire 43, require 12, search 7, misc 18; 164
1) to resort to, seek, seek with care, enquire, require 1a) (Qal) 1a1) to resort to, frequent (a place), (tread a place) 1a2) to consult, enquire of, seek 1a2a) of God 1a2b) of heathen gods, necromancers 1a3) to seek deity in prayer and worship 1a3a) God 1a3b) heathen deities 1a4) to seek (with a demand), demand, require 1a5) to investigate, enquire 1a6) to ask for, require, demand 1a7) to practice, study, follow, seek with application 1a8) to seek with care, care for 1b) (Niphal) 1b1) to allow oneself to be enquired of, consulted (only of God) 1b2) to be sought, be sought out 1b3) to be required (of blood)
In the above passage the word Darash(seek) is used in two ways . The first in regard to necromancy and the later those who speak according to the light of God word