While rejecting baptismal regeneration, Anthony A. Hoekema (Reformed) would agree that 1 Cor 12:13 is talking about the moment of regeneration; there is no room for the post-conversion “spirit baptism” /"second blessing" interpretation of some Pentecostal groups. Hoekema noted that 1 Cor 12:13
admits that the expression “in one
Spirit were all baptized into one body” does not refer to a post-conversion
“second-blessing” kind of experience, but refers to the uniting of all
believers to Christ in regeneration-conversion. It should then be noted that,
even on the Neo-Pentecostals’ own admission, Paul’s understanding of
Spirit-baptism is different from the common Neo-Pentecostal understanding of
that experience. For, whereas Neo-Pentecostals says that Spirit-baptism is an
experience distinct from conversion, Paul identifies Spirit-baptism with
conversion (or with regeneration with issues into conversion). . . . 1
Corinthians 12 is divinely inspired teaching about that baptism-teaching which
is normative or the church in all ages. The fact that Paul here teaches that
all Christians have been baptized in the Spirit at the time of regeneration
must therefore be decisive for our understanding of Spirit-baptism. . . . In 1
Corinthians 12:13 the expression describes the sovereign act of God whereby all
Christians are incorporated into the body of Christ at the time of
regeneration. Never in the New Testament is the expression “to be baptized in
the Spirit” used to describe a post-conversion reception of the totality or
fulness of the Spirit. (Anthony A. Hoekema, Holy Spirit Baptism [Exeter:
The Paternoster Press, 1972], 23, 24, 25)
