Protestans say:
Just read the Bible.
The Scriptures say:
"But know this first of all, that no prophecy of Scripture is a matter of one’s own interpretation,’ 2 Peter 1:20
“How can I understand unless someone guides me?” Acts 8:31
“There are some things in them hard to understand, which the unstable twist to their own destruction, as they do the other scriptures.” 2 Peter 3:16.
"Prescribe and teach these things. Let no one look down on your youthfulness, but rather in speech, conduct, love, faith and purity, show yourself an example of those who believe. Until I come, give attention to the public reading of Scripture, to exhortation and teaching. Do not neglect the spiritual gift within you, which was bestowed on you through prophetic utterance with the laying on of hands by the presbytery. Take pains with these things; be absorbed in them, so that your progress will be evident to all. Pay close attention to yourself and to your teaching; persevere in these things, for as you do this you will ensure salvation both for yourself and for those who hear you.
" I Timothy 4: