The service that belongs to God alone
If proskuneo is the body bowing, latreia is the cultic service — sacrifice, liturgy, the worship a creature renders to the Creator and to no one else. Jesus quotes Deuteronomy with the absolute: 'him ONLY shall you serve (latreuō).'
Worship as a life
Paul then stretches the temple word past the temple: present your body 'a living sacrifice… your latreia' (Rom 12:1). Worship is no longer one act in a building but a life laid on the altar. The exclusivity stays — this latreia, too, is for God alone.
Where This Word Decides Debates
Latreia anchors the latria-vs-dulia distinction in the icon/saints debate, and the biblical insistence that worship-service is owed to God alone.
When This Word Study Proves Too Much
Don't over-systematize: the New Testament uses the latreia/proskyneō pair flexibly, not as a fixed technical taxonomy. The exclusivity of worship to God is the firm point; the precise dulia/latria machinery is later development.