Isa 40:8, Isa 55:11, 1 Pt 1:24-25, Acts 28:30-31
The gospel that Jesus is the Christ is never bound. (1 Pt 1:24-25, Isa 40:8, Isa 55:11)
1 Pt 1:24 For all flesh is as grass, and all the glory of man as the flower of grass. The grass withereth, and the flower thereof falleth away: 25 But the word of the Lord endureth for ever. And this is the word which by the gospel is preached unto you.
Isa 40:8 The grass withereth, the flower fadeth: but the word of our God shall stand for ever.
Isa 55:11 So shall my word be that goeth forth out of my mouth: it shall not return unto me void, but it shall accomplish that which I please, and it shall prosper in the thing whereto I sent it.
Even though Paul is in prison, the gospel that Jesus is the Christ does not stop. (2 Tim 2:9, Acts 28:30-31)
2 Tim 2:9 Wherein I suffer trouble, as an evil doer, even unto bonds; but the word of God is not bound.
Acts 28:30 And Paul dwelt two whole years in his own hired house, and received all that came in unto him, 31 Preaching the kingdom of God, and teaching those things which concern the Lord Jesus Christ, with all confidence, no man forbidding him.