Philippians 2:17, 30

But even if I am being poured out as a drink offering on the sacrifice and service of your faith [for preaching the message of salvation], still I rejoice and share my joy with you all. [Num 28:7; 2 Tim 4:6]

because he came close to death for the work of Christ, risking his life to complete what was lacking in your service to me [which distance prevented you from rendering personally].