# God would open a door

Opening a door for someone is a metaphor for giving that person the opportunity to do something. Alternate translation: "God would provide opportunities" (See: [[rc://en/ta/man/translate/figs-metaphor]])

# open a door for the word

"make an opportunity for us tp preach his message"

# the secret truth of Christ

This refers to the gospel of Jesus Christ, which was not understood before Christ came.

# Because of this, I am chained up

Here "chained" is a metonym for being in prison. Alternate translation: "It is for proclaiming the message of Jesus Christ that I am now in prison" (See: [[rc://en/ta/man/translate/figs-metonymy]])