The reading is from St. Paul's Second Letter to the Corinthians 11:5-21

Brethren, I think that I am not in the least inferior to these superlative apostles. Even if I am unskilled in speaking, I am not in knowledge; in every way we have made this plain to you in all things.

Did I commit a sin in abasing myself so that you might be exalted, because I preached God's gospel without cost to you? I robbed other churches by accepting support from them in order to serve you. And when I was with you and was in want, I did not burden any one, for my needs were supplied by the brethren who came from Macedonia. So I refrained and will refrain from burdening you in any way. As the truth of Christ is in me, this boast of mine shall not be silenced in the regions of Achaia. And why? Because I do not love you? God knows I do!

And what I do I will continue to do, in order to undermine the claim of those who would like to claim that in their boasted mission they work on the same terms as we do. For such men are false apostles, deceitful workmen, disguising themselves as apostles of Christ. And no wonder, for even Satan disguises himself as an angel of light. So it is not strange if his servants also disguise themselves as servants of righteousness. Their end will correspond to their deeds.

I repeat, let no one think me foolish; but even if you do, accept me as a fool, so that I too may boast a little. (What I am saying I say not with the Lord's authority but as a fool, in this boastful confidence; since many boast of worldly things, I too will boast.) For you gladly bear with fools, being wise yourselves! For you bear it if a man makes slaves of you, or preys upon you, or takes advantage of you, or puts on airs, or strikes you in the face. To my shame, I must say, we were too weak for that!