Amen signifies divine confirmation from truth, consequently from the Lord himself because the Lord was truth itself. Therefore he so often said, "Amen I say unto you" (Matthew 5:18, 26, Revelation 3:14).

God is called the Amen, the faithful and true witness that the Lord is the truth itself. See John 14:16, 17, 19.

In Revelation 1:7, amen signifies divine confirmation. (Apocalypse Explained 40)

In Revelation 7:12, as the Lord was Truth Itself, He often said: AMEN, or VERILY, I say unto you. (Apocalypse Revealed 375, Apocalypse Explained 23)

(Referencias: Apocalypse Revealed 23, 292)

375. "Amen." This symbolizes the agreement of all.

This verse begins with the word "Amen," and now ends with it. When it is said at the beginning, it symbolizes truth and an affirmation in response to it (no. 371). But when it is said at the end, it symbolizes an affirmation and agreement by all that what has been said is the truth.