<p>13:9 <i>For we rejoice, when we are weak and you are strong- </i>The 'weakness' could mean that if they were truly strong in the Lord, then Paul would be 'weak' to administer discipline. <i>We </i>are weak and <i>you </i>are strong connects to the paradox established in 12:10, the only place where these words for &quot;weak&quot; and &quot;strong&quot; occur. Paul had learned that when <i>he</i> was weak, then <i>he </i>was strong. But now he speaks of how he wishes <i>his</i> weakness to be <i>their </i>strength. He wished the strength he experienced from his weakness to be shared with and experienced by them. The strength he gained through weakness was the strength of Christ; and he wished that same strength to be experienced by them. And he believed that his sufferings for them in his weakness could actually lead to their spiritual strengthening (see on :7). The same ideas are expressed in :4, where Paul says that the power of God which shall energize him is the same &quot;power of God toward <i>you</i>&quot;.</p><p><i>This we also pray for, even your perfecting</i>- Their perfecting was perhaps the outcome Paul wished to arise out of his visit to them; for he uses the same word in 1 Thess. 3:10 of how he longed to visit the Thessalonians and &quot;perfect that which is lacking in your faith&quot;. He would far rather that be the outcome to his visit than judgment unto condemnation. Again we see that the efforts of a third party, in this case through visiting weaker believers, could result in their spiritual strengthening towards salvation (see on :7). God is able to &quot;perfect&quot; the faith and spirituality of His children (Heb. 13:21; 1 Pet. 5:10); and this surely is done by the work of the Spirit on the hearts of believers. This is why Paul concludes by wishing that this process of perfecting s.w. &quot;mending&quot; would be permitted by them in their hearts (:11); and connected with this wish is his final desire that the <i>koinonia</i>, the participation &quot;fellowship&quot; of the Holy Spirit would be experienced by them.</p>