“I baptize you with water, but he will baptize you with the Holy Spirit.”
For we were all baptized by one Spirit so as to form one body—whether Jews or Gentiles, slave or free—and we were all given the one Spirit to drink.
There is something key that we “in Christ” have, that the church, Christ’s body- both local and universal has that the world does not. In the language of scripture, it is the baptism of the Holy Spirit. Christ poured out the gift of the Spirit after his ascension at Pentecost (see Acts 1 and 2).
We are baptized by, with or in the Holy Spirit, which in context speaks to our oneness in Christ, and in the larger context of scripture would seem to refer to the spiritual dynamic, or better put, filling of the Spirit given to the church, to all who are in Christ. This certainly becomes a reality for each person at conversion, and is gift that all of us in and through Christ have been given.
Often when this has been spoken about in recent times, it is referring to something like “a second work of grace,” or something more than what we receive at salvation. A tradition or interpreter might be able to make some sort of case for that from scripture. But essentially, it seems to me, along with the traditions I’ve been a part of at least for the most part, that this is all completely received at conversion. We are indeed blessed with every spiritual blessing in Christ (Ephesians 1), we’re told in Ephesians. Yet in that same letter, we’re also told to be filled with the Spirit (Ephesians 5). We have the gift of the Spirit, and therefore, we’re to live in the Spirit, edify each other in Christ by the Spirit, and be a witness to the world of the reality and truth of Christ and the gospel by the Spirit.
Our existence is “in Christ,” and the Spirit is the reality of that for us. We are humans, and yet taken up into the very life and mission of Christ. Both as individuals, and together as the church. That’s the difference maker for us, and really through us for the world in which we are to live and serve in love. In and through Jesus.