To say that all physical infants of believers are "in" the New Covenant as the infants of Abraham were "in" the Abrahamic and Sinaitic Covenants violates the doctrine of particular redemption.
I could not disagree more. IMHO this reveals a misunderstanding of what Paedos mean (at least this one and others—please note: there are “some” that stretch the issue of covenant too far) when we say a child is “in the covenant.” We say the phrase “in Covenant” with the understanding of a visible/invisible church distinction. Does everyone here understand visible and invisible distinction? Additionally, there is both a corporate and individual side to covenants both in the Old and New Testaments. The children lived in the camp, they ate the passover meal with their parents, and so forth. This does not mean they were necessarily saved (invisible church), but they did partake of the blessings (and many times the cursings) of the visible church. Even Fred says, “The Passover Lamb brought physical deliverance for all Israel because all ate it. The Annual Atonement (Lev. 16) was offered on behalf of the whole assembly, all Israel.” Clearly, children were included in the covenant just in a different way then “believers.” In EVERY covenant in the OT there were believers/unbelievers. In EVERY Church there are believers/unbelievers. In both the OC/NC there is a corporate and individual side of the covenant.

Reformed and Always Reforming,