‘Not that we have lordship over your faith, but are helpers of your joy. For in faith you stand fast.'
He wants them further to know that he is not suggesting that their faith depended on this, nor that he feels that he has the right to criticise their faith. That is between them and God. (He is not talking about the content of their faith, but the genuineness of it). And besides he knows that their faith is firm, that they stand fast in faith. But rather it was in order to establish their joy and ensure peace among them. It was the harmony and contentment of the church that he was concerned about.