It surprises me that Ridderbos does not begin with “ekklesia” as synonymous with, or continuation of, the Old Testament “qahal”, assembly. It appears somewhat in the third point of your summary, but almost as an afterthought. Connecting “qahal” and “ekklesia” also makes it harder to see the church as radically different from Israel– there is the discontinuity of unbelief but, in my view, also a continuation of the basic idea. Paul’s illustration of the olive tree in Rom 11 seems to agree with that.

Does Ridderbos address 1 Pet 2:9, “royal priesthood” applied to the church? This is a clear echo of Ex 19:6, where God calls Israel “kingdom of priests”. This raises two questions. (1) Doesn’t Peter’s application of Ex. 19 to the church emphasize continuity between Israel and the church? (2) Doesn’t this application negate, or reduce, the contrast between the ideas of church and “kingdom”?