It is neither baptism in water, nor repentance the "brings forgiveness of sins and the gift of the Holy Spirit". Rather only God can do that. Only God can forgive sins and give the gift of the Holy Spirit. However, baptism is the occasion, the time in the life of the sinner, when God has promised to forgive sins and give the gift of the Holy Spirit. That is the honest reading of Acts 2:38 and other passages.Nor do we see scripture that ones sins are forgiven and that he receives the Holy Spirit at the point of water baptism. Acts 2:38 and Acts 22:16 make it sound like our sins are forgiven at water baptism, but I believe that Peter's first command in Acts 2:38 "Repent" is what brought forgiveness of sins and the gift of the Holy Spirit, NOT the water baptism. Likewise, in Acts 22:16, Ananias told Saul to "call on the name of the Lord", which brought about his sins being washed away, NOT the water baptism.
As for Acts 22:16, Ananias didn't tell Paul (Saul) to call on the name of the Lord. Rather he instructed Paul to be baptized, calling on the name of the Lord. The baptism that Ananias was talking about was the same baptism that is presented in Acts 2:38, namely, it is baptism in the name of Jesus Christ. The very act of committing to being baptized is calling on the name of the Lord. Grammatically, in the Greek and also in English, calling is in the participial form modifying the verb baptized.
Eph 4:4 There is one body and one Spirit--just as you were called to the one hope that belongs to your call-- 5 one Lord, one faith, one baptism, 6 one God and Father of all, who is over all and through all and in all.Paul knew that all of the 120 believers on the day of Pentecost had already been baptized in water, when they decided to follow Jesus. John 4:1 But in Acts 1:5, they were told that they would receive a 2nd baptism called being "baptized with the Holy Spirit". Even before their 1st baptism, some of them had been baptized by John the Baptist. So that's 3 different baptisms.
There is only one baptism. It is in the baptism of the repentant believer that God forgives his sins and gives him the gift of the Holy Spirit. That is water baptism and that is the occasion of being baptized with the Holy Spirit. Being given the gift of the Holy Spirit is being immersed into the Holy Spirit. That is baptism with the Holy Spirit.