English Standard Version
If to others I am not an apostle, at least I am to you, for you are the seal of my apostleship in the Lord.New International Version
Even though I may not be an apostle to others, surely I am to you! For you are the seal of my apostleship in the Lord.Catholic Public Domain Version
And if I am not an Apostle to others, yet still I am to you. For you are the seal of my Apostleship in the Lord