2 Corinthians 8:23

8:23 If there is any question about Titus, he is my partner and fellow worker among you; if there is any question about our brothers, they are messengers of the churches, a glory to Christ.

2 Corinthians 12:12

12:12 Indeed, the signs of an apostle were performed among you with great perseverance by signs and wonders and powerful deeds.