Here "face death" represents knowing that he might die soon. He knew that some people wanted to kill him because they did not like what he was teaching.AT: "Every day I risk my life!" (See: [[rc://en/ta/man/translate/figs-metaphor]])
Paul uses this statement as evidence that he faces death every day. AT: "You can know that this is true, because you know about my boasting in you" or "You can know that this is true, because you know about how much I boast in you"
Paul boasted in them because of what Christ Jesus had done for them. AT: "my boasting in you, which I do because of what Christ Jesus our Lord has done for you" (See: [[rc://en/ta/man/translate/figs-explicit]])