Romans 16:25

16:25 Now to him who is able to strengthen you according to my gospel and the proclamation of Jesus Christ, according to the revelation of the mystery that had been kept secret for long ages,

Ephesians 3:3-4

3:3 that by revelation the divine secret was made known to me, as I wrote before briefly. 3:4 When reading this, you will be able to understand my insight into this secret of Christ.

Ephesians 3:9

3:9 and to enlighten everyone about God’s secret plan – a secret that has been hidden for ages in God who has created all things.

Revelation 10:7

10:7 But in the days when the seventh angel is about to blow his trumpet, the mystery of God is completed, just as he has proclaimed to his servants the prophets.”