en_tn/2co/01/23.md

I call God to bear witness for me that the reason ... was so that I might spare you

The phrase "bear witness" refers to a person telling what they have seen or heard in order to settle an argument. Alternate translation: "I ask God to show that what I say is true—that the reason ... was so that I might spare you" or "I ask God to witness for me that what I say is true: the reason ... was so that I might spare you"

so that I might spare you

"so that I might not cause you more suffering"