en_tn_lite_do_not_use/1co/04/15.md

ten thousand guardians

This is an exaggeration of the number of people guiding them, to emphasize the importance of the one spiritual father. Alternate translation: "very many guardians" or "a large crowd of guardians" (See: rc://en/ta/man/jit/figs-hyperbole)

I became your father in Christ Jesus through the gospel

Paul is emphasizing firstly that his relationship with the Corinthians is most importantly "in Christ," secondly that it came because he told them the good news, and thirdly that he is the one who is like a father to them. Alternate translation: "it was because God joined you to Christ when I told you the good news that I was the one who became your father"

I became your father

Because Paul had led the Corinthians to Christ, he is like a father to them. (See: rc://en/ta/man/jit/figs-metaphor)