The ESV translation of 1 Corinthians 12:13 reads accurately as follows: “For in one Spirit we were all baptised into one body— Jews or Greeks, slaves or free—and all were made to drink of one Spirit.” The phrasing in Greek typically indicates baptism in, and not by, the Spirit (as seen in Matthew 3:11; Mark 1:8; Luke 3:16; and Acts 1:5). Here, water baptism is not in consideration since this chapter refers to the work of the Holy Spirit in gracing Christians with unique gifts. So what is this baptism, referred to here by Paul but extensively, too, by Luke in the book of Acts?
It is the ultimate empowerment for Christian service and initiates any Christian receiving it to maximum effectiveness in their service of God. This view is acknowledged by over 600 million Pentecostals and Charismatics worldwide who now represent the largest sector within Christendom, aside from Catholicism (yet many Catholics are Charismatics and a high proportion are also very nominal, so the lines are somewhat blurred).
Although Spirit Baptism may (and perhaps should) happen at conversion, there are practical reasons why this may not (and usually does not) take place. Baptism is really one Christian initiation in two parts, where water baptism represents a public and mature identification of the inward faith which distinctly marks eternal salvation (the Bible does not endorse infant baptism). But Spirit Baptism is the receipt of the Spirit’s overflowing fullness, as with the experience of Acts 8:14-17, which cannot be explained as a unique exception (as it is by some) when it confirms similar occurrences in Acts 2:1-4, Acts 10:44-48 and Acts 19:1-7. The last of these passages also shows a subsequence in the full receipt of the Spirit, even though it is clearly a part of the overall process of full surrender to the work of Christ. In all of these cases, there is also visible evidence of the event and this is typically, if not universally, the gift of supernatural languages (“tongues”).
Certainly, an absence of supernatural gifts during Spirit Baptism might lead one to wonder how they would know themselves to be filled with the Spirit anyway, even though every Christian must have a measure of the filling of the Spirit in order to confess Christ as Lord (1 Corinthians 12:3). Tongues and other such gifts have purposes clarified in Scripture and they cannot be consigned to history, or explained away as unorthodox, when they find expression globally today. Whatever the subtle distinction between Christian traditions, the balance of widespread experience and abundant biblical textual support surely show Spirit Baptism to be an endowment of power that continues to see amazing personal transformation and miraculous encounters in the lives of all Christians who remain open to this fullness of God’s work in the Earth today.