This is an obvious sign of the righteous judgment of God, to the end that you may be counted worthy of the Kingdom of God, for which you also suffer.
A manifest token...New Testament only here. Compare Philippians 1:28. The token is the patience and faith with which they endure persecution and tribulation. It is a token of the righteous judgment of God, in that it points to the future glory which God will confer at the final judgment, and the righteous award which will be dispensed to the persecutors (Vincent, Vol. IV 54).