What is an overview of the doctrines held by various Christian denominations concerning God's revelation of mysteries to spiritual seekers?

Ruminator's question https://christianity.stackexchange.com/q/108102/117426 prompted me to compile a list of [Biblical passages](https://christianity.stackexchange.com/a/108109/117426) that discuss mysteries, hidden knowledge, secrets of the Kingdom, and related themes, as well as God's willingness to invite seekers to search these things out. Ruminator also assembled an extensive collection of passages in his own [answer](https://christianity.stackexchange.com/a/108106/117426) on the theme of mystery in the Bible. Interestingly, some of the answers and comments in the linked question appear to advocate a kind of cessationist position, suggesting that everything has already been revealed in the Bible, and therefore no mysteries remain to be disclosed (or so they seem to argue). With this in mind, I am interested in an overview of doctrines from various denominations—including Catholicism, Eastern Orthodoxy, and Protestantism—regarding the possibility of God revealing mysteries to spiritual seekers today. It is evident from the Bible that God has certainly revealed mysteries to individuals in the past—for example, Paul's experience of the third heaven in 2 Corinthians 12:2-4, where he received revelations not recorded in Scripture. The question, however, is whether this possibility is still considered viable today, doctrinally speaking, and what conditions, if any, are believed to govern access to such mysteries. Would it be reasonable for a spiritual seeker to earnestly desire the revelation of mysteries today, according to different denominations?