Apostle Paul uses the term “mystery” in reference to Jesus Christ to emphasize that God’s plan of salvation—which was once hidden from the world and known only to God—is now revealed and accessible through the incarnation and presence of Christ in the lives of believers.

Unveiling the Hidden Plan

Apostle Paul uses the term “mystery” in reference to Jesus Christ to emphasize that God’s plan of salvation—which was once hidden from the world and known only to God—is now revealed and accessible through the incarnation and presence of Christ in the lives of believers. Paul demonstrates that what was concealed “from ages” and “from generations” has now been unveiled in the New Testament, where Christ has become the focal point of divine revelation and salvation.

For example, one source states:
“Hidden from ages, – he says, – and from generations. And rightly he called secret that which no one knew except God.

Where is the secret?

In Christ, as is said in the epistle to the Ephesians, or as the prophet once said: from age to age You are God” (source: link txt).
This passage indicates that true knowledge of God and His plan was hidden throughout history and is now made manifest through Christ.

Similarly, another text emphasizes the personal incarnation of this mystery:
“Moreover, it was necessary to learn that He who is above all, who rules over the angels and has authority over all other powers, came down, became Man, underwent innumerable sufferings, was resurrected and ascended. All of this was the result of the mystery, and Paul solemnly proclaims it when he says: who is Christ in you. If He is in you, then why do you seek teachers from among angels? In this mystery” (source: link txt, page: 528).
Here, the focus is on the fact that the mystery of God’s plan is revealed through Christ’s personal presence in the hearts of believers, standing in opposition to any external authorities and demonstrating that salvation is achieved through direct communion with God.

Thus, Paul’s definition carries the following significance: through the incarnation, Christ reveals to the world the divine plan of salvation that was previously hidden. This mystery shows that salvation and God’s wisdom are available not only as abstract knowledge but also as the real presence of the Lord in the life of every believer, profoundly changing the understanding of God and human salvation.

Supporting citation(s):
“Hidden from ages, – he says, – and from generations. And rightly he called secret that which no one knew except God.

Where is the secret?

In Christ, as is said in the epistle to the Ephesians, or as the prophet once said: from age to age You are God” (source: link txt).
“Moreover, it was necessary to learn that He who is above all... All of this was the result of the mystery, and Paul solemnly proclaims it when he says: who is Christ in you... In this mystery” (source: link txt, page: 528).