9 We are glad whenever we are weak but you are strong; and our prayer is that you may be fully restored.

Read 2 Corinthians 13:9 Using Other Translations

For we are glad, when we are weak, and ye are strong: and this also we wish, even your perfection.
For we are glad when we are weak and you are strong. Your restoration is what we pray for.
We are glad to seem weak if it helps show that you are actually strong. We pray that you will become mature.