Does Exclusion from Membership Amount to Excommunication?

Thoughts from John L. Dagg On page 73 (at the bottom of this link in the free electronic version - chapter 1, section 5) of John L. Dagg's Treatise of Church Order, he states that "none but baptized persons can be admitted to membership." One of Piper's points in his disagreement with Wayne Grudem is that those who are excluded from church membership because they have not been scripturally baptized are treated as though they have been excommunicated from the church. Dagg addresses this concern as it relates to communion, in his chapter on that topic. Although he is speaking about the inclusion or exclusion from the Lord's Table of one who believes in infant baptism, application can be made beyond that to speak to the issue of church membership for anyone not scripturally baptized (including those not claiming to be baptized at all). The bottom line is whether we are treating these ordinances according to the will of the Lord revealed in His Word. Dagg's interaction with this argument is below.

Argument 7.--To exclude a Pedobaptist brother from communion, is substantially to inflict on him the punishment of excommunication, the punishment inflicted on atrocious offenders. Such is not the proper treatment of a fellow disciple, whose error of judgment the Lord graciously pardons.

When an advocate of open communion excludes from the Lord's table an amiable neighbor, who does not give evidence of conversion, the exclusion is not regarded as a punishment. Neither ought our exclusion of the unbaptized; much less is it right to speak of it as the punishment inflicted on atrocious offenders. The churches have no scale of penalties adjusted to different grades of crime. When they excommunicate, they withdraw their fellowship, and this may be done for wrongs of very different magnitude. There is no necessity to class the error of pedobaptism with the most atrocious of these wrongs. The church which excludes a Pedobaptist from the Lord's table, does not design to inflict a punishment on him, but merely to do its own duty, as a body to which the Lord has intrusted one of his ordinances. The simple aim is, to regulate the observance according to the will of the Lord.