2 Corinthians 3:14; 2 Corinthians 7:13; 2 Corinthians 11:7; 2 Corinthians 11:11

14 But their minds were hardened; for until this very day at the reading of the old covenant the same veil remains unlifted, because it is removed in Christ.
13 For this reason we have been comforted. And besides our comfort, we rejoiced even much more for the joy of Titus, because his spirit has been refreshed by you all.
7 Or did I commit a sin in humbling myself so that you might be exalted, because I preached the gospel of God to you without charge?
11 Why ? Because I do not love you? God knows I do!