en_tn/php/02/30.md

he came near death

"he almost died." Paul speaks of dying as if death were a place that people could go to. (See: rc://en/ta/man/jit/figs-metaphor)

so that he could bring to completion what was lacking in your service to me

The meanings of the abstract nouns "completion" and "service" can be expressed as verbs. Alternate translation: "so that he could complete what you could not do in serving me"