Revelation 10:7
But in the days when the seventh angel is ready to sound his trumpet, then the secret plan of God will be accomplished, just as He [had] announced to His servants the prophets."
Romans 16:25
Now may there be glory for ever, through Jesus Christ, to the only wise God, who is able to make you stand firm [in the faith], according to the good news and proclamation of Jesus Christ. This message is the secret which was [eventually] revealed, after having been kept quiet about for long ages.
Luke 24:44-47
Then Jesus said to the apostles, "These are the words that I told you while I was still with you, [when I said] that everything written in the law of Moses, and the prophets, and the psalms about me needed to be fulfilled."
Acts 3:21
who must be received into heaven until [God's appointed] times when everything will be restored [to its intended purpose]. God had spoken about this through the proclamations of His holy prophets of long ago.
Romans 11:25
For I want you to know this secret, brothers, so you will not become conceited: Part of the Israelites have become [spiritually] insensitive [to God], [and will remain that way] until the fullness of the Gentiles occurs. [Note: As with verse 12, concerning the Jews, "fullness" here may mean either a large or the complete number of Gentiles who will be saved].
Ephesians 3:3-9
[It is] that God's secret plan [i.e., revealed in the Gospel preached to Gentiles. See verse 6] was made known to me by way of a revelation. [See Acts 9:15; 22:21]. I have already written to you [about this] briefly [i.e., probably a reference to 1:9ff].
Revelation 11:15-18
Then the seventh angel sounded its trumpet, and there were loud voices in heaven saying, "The kingdom of the world has become the kingdom of our Lord [i.e., God] and of His Christ, and He will rule forever and ever."