which are a sign of the just judgment of God, so that you may be held worthy of the kingdom of God, for which you also suffer
Other versions
King James Version
Which is a manifest token of the righteous judgment of God, that ye may be counted worthy of the kingdom of God, for which ye also suffer:English Standard Version
This is evidence of the righteous judgment of God, that you may be considered worthy of the kingdom of God, for which you are also suffering--New International Version
All this is evidence that God's judgment is right, and as a result you will be counted worthy of the kingdom of God, for which you are suffering.