2 Corinthians 11:30-33

If I must boast, I will boast of the things that show my weakness.

(v30, NIV)

This is completely weird. Who the heck boasts about their weakness? People boast about all sorts of things, but never about their weakness. Weaknesses do not make you look good or anything. It's not a means of showing pride in. Yet, it's almost like Paul takes pride in it.

But he said to me, "My grace is sufficient for you, for my power is made perfect in weakness." Therefore I will boast all the more gladly about my weaknesses, so that Christ's power may rest on me.

(2 Corinthians 12:9, NIV)

So there is reason to boast in weakness. Paul is reassured of his weakness. However, I don't want to go too much into it. I'll get there soon enough.

The God and Father of the Lord Jesus, who is to be praised forever, knows that I am not lying.

(v31, NIV)

People may not have believed Paul. The things he is saying are hard to believe. Whether it is his credentials, or the gospel they have turned away from, or his love for them, or even his claim to boast in his weakness, they have a hard time believing Paul. However, he asserts to them that God supports his claims. God's lie detector does not reveal any lies.