The Ethiopian Eunuch is often cited as an example of someone who was not baptized into a local church. His baptism is then made the precedent for overturning everything else that the New Testament teaches about the coincidence of baptism and church membership. Several important objections must be made against this use of the passage. First, if the Ethiopian Eunuch indeed was not baptized into a local church, it was only because no such church existed in Ethiopia. This was clearly an exceptional circumstance that must not be made into a normative principle of the church or applied to situations where a local church does exist. Second, it is not, in fact, clear that the Ethiopian Eunuch was not baptized into a local church. This assumption on the part of interpreters is nowhere stated in the passage. It is possible and even probable given the teaching of the rest of the New Testament that he was baptized into the membership of the church in Jerusalem or that he was the first member of the church in Ethiopia. One thing is for sure this is no instance of happy-go-lucky evangelism where believers are made and then left to fend for themselves. We cannot attribute such a practice to Philip or the church in Jerusalem.
The only alternative to saying that Christians are baptized into the visible and local church is to say that they are baptized into the invisible and universal church. This is to misconceive the relation between the universal and local church.
At bottom a failure to see the connection between baptism and church membership is rooted in a failure to see that the local church is the only appointed, visible expression of the universal church. It is rooted in a misconception of the relation between the universal and local church. In 1 Timothy 3:15 it is plainly the universal church that is described in the language “the household of God, which is the church of the living God, the pillar and support of the truth.” Just as clearly when Timothy is instructed as to how he ought to conduct himself in that church in the ordering of its public meetings and the setting apart of its officers (1 Tim. 2:1-3:15) and in his own ministry (1 Tim. 4:1ff.), the local church at Ephesus is viewed as the visible expression of that church. It is impossible, then, to argue that baptism joins one (visibly) to the universal church without seeing that at one and the same time this must make one a member of the local church where one is baptized. So to argue is to misconceive the relation between what we call the universal and local church.Sam Waldron Professor of Systematic Theology at Midwest Center for Theological Studies .