Listening to Peter's speech in Acts 2, it sounds as though baptism was a first step prior to the receiving of the Holy Spirit.
It's pretty common doctrine to say that baptism is not required for salvation. And it's pretty common doctrine it to say that sanctification is not possible with out being empowered by the Holy Spirit. So, is sanctification not possible without baptism?
The broader question is whether Peter is being descriptive of local circumstances or prescriptive for future Christians.