We are bound to always give thanks to God for you, brothers,{The word for "brothers" here and where context allows may also be correctly translated "brothers and sisters" or "siblings."} even as it is appropriate, because your faith grows exceedingly, and the love of each and every one of you towards one another abounds;
So Paul is saying that we are actually, we glory in you when we go around and share in the other churches. We glory in what God has done in you; we love to share what the Lord is doing there for you.