"Who are those to whom these mysteries are revealed? Who are the initiated? To whom does God reveal the mystery of Christ? Now, there may be of course many mysteries of the kingdom, but the comprehensive mystery is the mystery of Christ and the answer is very simple. It is twofold. First, we see it is to those who are born of God. It is as simple as that. It is the birthright of every born-again believer."
... but now hath it been manifested to His saints, to whom God was pleased to make known ...
what is this mystery.
Colossians 1:26-27
Secondly, it is by revelation through the Holy Spirit.
We cannot know the things of God except by
the Spirit of God, which has been given to us
1 Corinthians 2:11-12
Come explore the mystery of Christ. May the Lord give revelation of His heart.