1 Corinthians 5:4

In the name of our Lord Jesus Christ--By His authority and as representing His person and will (Co2 2:10). Join this with "to deliver such a one unto Satan" (Co1 5:5). The clause, "When ye have been gathered together and my spirit (wherein I am 'present,' though 'absent in body,' Co1 5:3), with the power of our Lord Jesus," stands in a parenthesis between. Paul speaking of himself uses the word "spirit"; of Christ, "power." Christ's power was promised to be present with HIS Church "gathered together in His name" (Mat 18:18-20): and here Paul by inspiration gives a special promise of his apostolic spirit, which in such cases was guided by the Holy Spirit, ratifying their decree passed according to his judgment ("I have judged," Co1 5:3), as though he were present in person (Joh 20:21-23; Co2 13:3-10). This power of infallible judgment was limited to the apostles; for they alone had the power of working miracles as their credentials to attest their infallibility. Their successors, to establish their claim to the latter, must produce the former (Co2 12:2). Even the apostles in ordinary cases, and where not specially and consciously inspired, were fallible (Act 8:13, Act 8:23; Gal 2:11-14).

— Jamieson-Fausset-Brown Commentary (public domain)