God would continue to strengthen Paul and keep him strong in faith until the end of his life (4:7; see 1:12).
The Lord’s heavenly kingdom is different from this kingdom of earth that was about to judge Paul (see also 4:1; 1 Corinthians 15:48–49; Hebrews 12:18–29).
glory … Amen: Paul’s praise of God, even when facing death, shows his belief that God’s glory will remain (compare 1 Timothy 1:17; 6:15–16).
to Him: The Greek text implies this praise is for “the Lord” in the previous sentence, specifically referring to Jesus (compare Titus 2:13).