‘Jesus’ disciples prophesied “in his name” (Mt. 7:22), cast out demons “in his name” (Lk. 10:17), performed miracles “in his name” (Mk. 9:39), etc. With the use of this expression it becomes evident that the disciples spoke and acted like Jesus, in His place and with His authority, as did the prophets of Yahweh in the OT (see Acts 4:7–10). Similarly, the gospel is to be preached in all the world “in his name,” i.e., by His authority, and thus be made effectual to save people (Lk. 24:47), justify sinners (Acts 10:43), and forgive people their sins (1 Jn. 2:12).’

G.W. Hawthorne, ISBE (2nd ed.), art. ‘Name’