The truth regarding the finality of God's initiative in Christ is conveyed by one word of the Greek Testament, namely the adverb hapaxand ephapax. It is usually translated in the Authorized Version once, meaning once for all. It is used of what is so done as to be of perpetual validity and never need repetition, and is applied in the NT to both revelation and redemption. Thus, Jude refers to the faith which was once for all delivered to the saints (Jude 3), and Romans says, " Christ also died for sins once for all" (Rom.6:10, see also 1 Pe.3:18; Heb.9:26-28).
Thus we may say that God has spoken once for all and Christ has suffered once for all. This means that the Christian revelation and the Christian redemption are both alike in Christ complete. Nothing can be added to either without being derogatory to Christ... These are the two rocks on which the Protestant Reformation was built -- Gods revealed word without the addition of human traditions and Christ's finished work without the addition of human merits. The Reformers great watchwords were sola scripturafor our authority and sola gratiafor our salvation.
|--John R. W. Stott, Christ the Controversialist,InterVarsity Press 1978, pp.106-107|