what to call it?

The answer to what to call this thing often referred to as baptism in the Spirit is "being filled with the Spirit”. Not only is this phrase found in Scripture, but it is frequently used in contexts that speak of Christian growth and ministry. Wayne Grudem explains as follows:

Paul tells the Ephesians, “Do not get drunk with wine, for that is debauchery; but be filled with the Spirit” (Eph. 5:18). He uses a present tense imperative verb that could more explicitly be translated, “Be continually being filled with the Holy Spirit,” thus implying that this is something that should repeatedly be happening to Christians. Such fullness of the Holy Spirit will result in renewed worship and thanksgiving (Eph. 5:19–20), and in renewed relationships to others, especially those in authority over us or those under our authority (Eph. 5:21–6:9). In addition, since the Holy Spirit is the Spirit who sanctifies us, such a filling will often result in increased sanctification. Furthermore, since the Holy Spirit is the one who empowers us for Christian service and gives us spiritual gifts, such filling will often result in increased power for ministry and increased effectiveness and perhaps diversity in the use of spiritual gifts.

We see examples of repeated filling with the Holy Spirit in the book of Acts. In Acts 2:4, the disciples and those with them were “all filled with the Holy Spirit.” Later, when Peter was standing before the Sanhedrin, we read, “Then Peter, filled with the Holy Spirit said to them...” (Acts 4:8). But a little later, when Peter and the other apostles had returned to the church to tell what had happened (Acts 4:23) they joined together in prayer. After they had prayed they were again filled with the Holy Spirit, a sequence of events that Luke makes clear: “After they prayed, the place where they were meeting was shaken. And they were all filled with the Holy Spirit and spoke the word of God boldly” (Acts 4:31 NIV). Even though Peter had been filled with the Holy Spirit at Pentecost (Acts 2:4) and had later been filled with the Holy Spirit before speaking to the Sanhedrin (Acts 4:8), he was once again filled with the Holy Spirit after the group of Christians he was meeting with had prayed.

Filling with the Holy Spirit is not a one-time event but is an event that can occur over and over again in a Christian’s life. It may involve a momentary empowering for a specific ministry (Acts 4:8; 7:55) or it may refer to a long-term characteristic of a person’s life (Acts 6:3; 11:24). Stephen serves as an example of both. He was a man “full of the Spirit and of wisdom” (Acts 6:3, 5), yet when he was being stoned he received a fresh new filling of the Holy Spirit in great power (Acts 7:55).