Archomai is the middle-voice form of archō, meaning "to begin" or "to start doing something." Appearing about 86 times in the NT, it is commonly followed by an infinitive: "he began to teach" (ērxato didaskein), "they began to speak" (ērxanto lalein). It is distinct from the active archō meaning "to rule/govern." The word carries the Greek concept of archē (beginning, origin, first principle) at its root.
The concept of beginning (archē) is foundational to the NT's theological framework. John 1:1 echoes Genesis 1:1: "In the beginning (en archē) was the Word." Jesus' ministry is repeatedly described with archomai — marking inaugurated fulfillment. Luke uses it to signal new divine action: the Spirit leads, then Jesus "begins." Acts uses it structurally (Acts 1:1 — "all that Jesus began to do and teach"). The implication is that what Jesus began in His incarnation, He continues through the Spirit and the Church — the story is not over.